A systematic review of intergenerational co-residence between older people and adult children

ABSTRACT

This study explores intergenerational co-residence, explicitly focusing on the decision-making factors of older adults and their adult children. While previous research has touched on this topic, only a few studies have truly evaluated the factors driving both generations’ willingness to embrace this living arrangement. This study systematically reviews the factors influencing older and younger adults’ willingness to live in intergenerational households. Systematic searches were conducted through five databases: CINAHL, Embase, PsycINFO, PubMed, and Scopus; all studies until September 2022. Of the 467 articles initially identified, 17 articles were retained for data extraction. Extracted data were divided into two groups: older people’s and adult children's perspectives. Data extraction revealed six factors influencing older adults’ decision to live with their children, encompassing financial circumstances, health conditions, kinship systems, marital status, level of education, and number of family members. Similarly, these factors are relevant for adult children, except for health conditions. The interconnection between these factors and their dynamics is contingent upon the specific context of each region’s population.

KEYWORDS:

• Adult children
• family
• intergenerational co-residence
• older people
• systematic review

Introduction

The Department of Economic and Social Affairs of the United Nations (2020) reported that there are three standard living arrangements for older adults: living alone, living with children, and living in institutions. Other arrangements also exist, including living with extended family, skip generation, and non-relative persons. However, most older people prefer to live with their adult children, even in the more developed countries (Ruggles, 2007). Co-residence between the two generations mainly occurs during the later life of older people (Reher & Requena, 2018). Older people tend to protect their autonomy by living alone to have the freedom to manage their daily activities (Meng et al., 2017). However, their health conditions may require them to live with a caregiver, more often their adult child (Gonzales, 2007; Lee et al., 1995; Reher & Requena, 2018).

In Asian cultures, there is a strong emphasis on filial piety, where adult children are obligated to provide a place to live with their parents (Chen & Jordan, 2019; Chen et al., 2022; Chu et al., 2011; Kim et al., 2017; Zhang et al., 2014). Moreover, some countries have limitations on social protection programmes due to government regulations that make co-residence the best solution for giving intergenerational support. Living together allows adult children to support their parents, and older people can support their children with their daily responsibilities (Beard & Kunharibowo, 2001; Casares & White, 2018; Chen & Jordan, 2019; United Nations Department of Economic and Social Affairs, 2020; Ward & Spitze, 2007; Zhang et al., 2014).

This mutual support between older people and their adult children can impact both generations positively and negatively. Co-residence can help both generations to assist each other (Chen & Lewis, 2015; Liu et al., 2018; Meng et al., 2017; Yasuda et al., 2011), which helps older people maintain their psychological well-being (Kim et al., 2017; Setiyani et al., 2019; Wang et al., 2014) and life satisfaction (Chen et al., 2021; Chen & Jordan, 2019; Liu et al., 2018). Conversely, co-residence can also negatively impact the parent–child relationships. Too much support from adult children can reduce the autonomy of older people and lower their psychological well-being (Silverstein & Bengtson, 1994). Co-residence may also influence the quality of the relationship between parents and their adult children. [edited for anonymous review] shows that the detrimental dynamics between older people and their adult children exert more influence on their psychological well-being compared to the positive aspects.

Furthermore, a review by Zhao (2023) found that the welfare management policies for older people play an important role in influencing the living arrangements of older people in China. Similarly, intergenerational co-residence in the United States has been shown to be influenced by shifts in social welfare policies and ethnic demographics (Keene & Batson, 2010). Along with this result, a review of intergenerational co-residence in North America also highlighted the importance of demographic, economic, and ethnic identities in influencing intergenerational co-residence (Mazurik et al., 2020). Roy et al. (2018) conducted a systematic review highlighting the role of older people’s health conditions as a determinant of intergenerational co-residence in countries such as the United States, Australia, Canada, and various European nations. However, health deterioration prevents older people in Indonesia from living with their children (Johar & Maruyama, 2011).

Hence, we assume that intergenerational co-residence is a complex issue that can be influenced by various factors, including demographic, economic, social, and cultural circumstances. A factor that significantly impacts intergenerational co-residence in one geographical area may not necessarily yield the same impact in another region. Also, we suspect that ageing parents and adult children will have different considerations regarding this living arrangement. Ward and Spitze (1992) reviewed many studies about co-residence by parents and adult children and suggested further research on the motivations that influence the decision of older adults and their children to live in intergenerational households was required. Thus, the primary objective of this study is to find the determinant factors behind the participation of older people and adult children in intergenerational co-residence. This will be achieved through an extraction of empirical studies with a systematic review approach.

Design and methods

This study uses a systematic review framework to identify and retrieve the evidence on factors influencing the engagement of older people and adult children in intergenerational co-residence. The authors screened and ensured that all the studies in this systematic review followed the inclusion criteria. All the processes of this systematic review were conducted through Covidence. An expert librarian from The University of Queensland, Australia, also reviewed the search strategy in this study. In addition, we registered this systematic review with PROSPERO (CRD42022361694).

Ethics approval

This is a systematic review; as such, it involves secondary data analysis of published material and does not require ethics committee approval.

Search strategy and study selection

This systematic review had three steps in searching and selecting studies. The first was a comprehensive search of several databases to ensure that this review located studies from multiple countries and research fields related to intergenerational co-residence between older people and adult children. The databases included CINAHL, Embase, PsycINFO, PubMed, and Scopus. We searched all studies until September 2022.

Search terms included a combination of Medical Subject Headings (MeSH) indicative of (1) intergenerational relations, (2) co-residence, (3) parent-adult child co-residence, (4) adult children, (5) elderly, and (6) well-being. Studies were included in this systematic review if they met the following criteria: (1) the study's primary focus was the intergenerational co-residence dynamics between older people and their adult children; (2) original empirical studies with research methods explicitly reported; (3) all study designs, except systematic, scoping, and literature reviews; (4) the full-text article was accessible. In total, we retrieved 467 articles from the five databases.

Next, titles and abstracts were screened, and duplicates were removed. A further 342 articles were removed based on the inclusion and exclusion criteria, including studies focused on young child populations. Due to the aim of this study, we excluded research involving older adults facing terminal illnesses or psychological disorders like depression and anxiety. The existence of an illness in an aged parent tends to heighten the social expectations on adult children to provide more intensive care. Consequently, intergenerational co-residence is likely to be influenced by the parents’ health conditions rather than the voluntary choice of adult children to share a residence. Also, we excluded studies about ageing stigma, neurocognitive problems, and older people who lived in the institutions. We omitted studies that included adult–child participants with developmental issues. These exclusion criteria aimed to ensure that the included studies were focused on a representative sample of older people and adult children. That is, engagement in intergenerational co-residence was not due to the need to assist another generation's disability.

The full-text review consisted of 42 articles. This review defined intergenerational co-residence as between ageing parents and their adult children who were otherwise old enough to live independently. We excluded all publications that were book chapters and dissertations and only included peer-reviewed articles. We give preference to research that has undergone a rigorous peer review process to ensure its quality. Hence, our priority is to utilise empirical research published in academic journals over other formats. Two authors, LH and TR, conducted review processes independently, with the second author (PN) resolving any disagreements. In the end, 17 studies were retained for data extraction. Figure 1 outlines these steps.

Figure 1. The screening process flow based on Covidence.

Extraction and data analysis

A data extraction form was created through Covidence with the following components: research location, research objective, methods, participants, indicators of intergenerational co-residence for older people, and indicators of intergenerational co-residence for adult children. In addition, we also completed a quality assessment for every study we reviewed with the Mixed Methods Appraisal Tool (MMAT) Version 2018 (Hong et al., 2018). For example, the clarity of the research question, the data collection process following the research question, the appropriateness of the study design to answer the research question, and whether the interpretation of the results was sufficiently substantiated by the data. This data extraction process was led by the first author (LH) and checked by the third author (TR). Disagreements were resolved by a second author (PN).

Findings

This study aimed to identify the factors influencing older people's and adult children's engagement in intergenerational co-residence. From the 17 articles initially identified for this systematic review, we found that only eight provided data about the factors that motivated adult children to participate in intergenerational co-residence; 16 of these articles evaluated the willingness of older people to live with their adult children. Most of the studies included in this systematic review focused on community-based populations in rural and urban areas, with one study focused solely on the adult child population in rural areas (VanWey & Cebulko, 2007). Table 1 summarises the 17 articles included in this systematic review.

Table 1. The studies summary.

No.	Source	Location	Objectives	Inclusion criteria	Exclusion criteria	Research method	Outcomes
1	Chen (2019)	China	Investigating the determinants of preference for intergenerational co-residence and examining the effect of living arrangement concordance of older Chinese.	Older adults aged 60 years and older at the time of the survey and had at least one surviving child.	–	Cross-sectional study	Older adults brought up in urban areas, where cultural prescriptions and expression tend to be less traditional, were less likely to prefer co-residence. Also, the education levels of older people are regarded as an indicator of their ability to live independently. Actual living arrangements are highly predictive of the preference of older people to engage in intergenerational co-residence.
2	Choi (1995)	United States	Investigating the racial differences in the likelihood of intergenerational co-residence and contact frequency between ageing parents and their adult children.	Elderly persons aged 70 years and over in 1984 had at least one living child aged 18 and over.	Interview data from other years, except 1988.	Cross-sectional study	There is a racial difference in intergenerational co-residence when the parent's marital status is controlled. Married non-Hispanic older people are less likely to live with their adult children than African American older people.
3	Choi (2003)	United States	Finding the differences between the nonmarried parents’ and children's characteristics associated with continuing co-residence versus transitioning into or out of co-residence.	Community-dwelling men and women aged 70 and older and their co-residing adult children or grandchildren.	Older people who lived with their children or grandchildren who were under 21 years old or lived with other than their biological children.	Longitudinal study	There are no significant differences between ageing parents who are no longer co-residing with their children and those who are continuously co-residing.
4	Domingo and Asis (1995)	Philippines	Exploring the family's role in caring for the elderly, particularly in the face of rapid social change.	Elderly (in the ages 60–85) and adult children (ages 35g to the practice of intergenerational co-resid55)	–	Qualitative research	Intergenerational co-residence could make ageing parents feel the burden of supporting other family members or fear being the burden for their adult children. Conversely, adult children found difficulties being the sandwich generation and the need to be patient in caring for ageing parents.
5	Gerber et al. (2019)	United States	Investigating the impact of intergenerational co-residence on older people’ affect.	Older adults aged 50–74 years old.	–	Cross-sectional study	Co-residence has a significant positive impact on parents’ negative affect and a significant negative impact on parents’ positive affect. Also, parental income level significantly moderates the association between co-residence and parental affect.
6	Gonzales (2007)	United States	Examining a more direct measure of cultural values, alongside English language proficiency, socioeconomic resources, need, and child network characteristics, as the co-residence determinants	Non-institutionalised persons ages 65 and older who may have been born in or immigrated to the United States. They should at least have one surviving child.	–	Longitudinal study	A stronger belief in traditional cultural support values will increase the likelihood of co-residence with an adult child, where more educated parents are less likely to co-reside with an adult child. Conversely, parents with more economic resources are more likely to live with an adult child.
7	Isengard and Szydlik (2012)	Sweden; France; The Netherlands; Denmark; Belgium; Germany; Austria; Switzerland; Spain; Greece; Italy	Exploring the characteristics of co-residence between adult children and their parents.	People aged 50 years and older from 11 European countries: Sweden, Denmark, the Netherlands, Belgium, Germany, Austria, Switzerland, France, Spain, Italy, and Greece.	–	Cross-sectional study	Several factors influence adult children's and their parent's engagement in cohabitation: the child's employment status and education levels, parents’ income, parental house, parents’ health, and the family structure.
8	Johar and Maruyama (2011)	Indonesia	Investigating factors influencing cohabitation decisions by ageing parents and their adult children.	Elderly individuals 60 years of age and older with at least one surviving adult child (15 years old and older).	–	Longitudinal study	Cohabitation is influenced more significantly by the costs and benefits of children. Wealthy parents live with their children who still depend upon their parents.
9	Johar et al. (2015)	Japan	Investigating the determinants of parent-child co-residence in Japan.	Japanese aged 65 and over with at least one surviving child.	Older parents who live with other than their biological children and live in the institution.	Longitudinal study	Intergenerational co-residence responds to the heightened care needs of parents, including the loss of a spouse and health deterioration. Also, ageing parents who are engaged in this living arrangement usually have sizeable assets that make them capable of supporting their children.
10	Ken and Teerawichitchainan (2015)	Vietnam	Examining the relationship between living arrangements and the psychological well-being of older adults.	Older adults aged 60 and older who had at least one living child at the time of the survey.	–	Cross-sectional study	Intergenerational co-residence has a positive and significant impact on the psychological well-being of older adults.
11	Lee et al. (1995)	Taiwan	Expanding the understanding of living arrangements by presenting systematic qualitative results from focus groups conducted with ageing parents and younger adults in Taiwan.	Older adults aged 60–85 and younger adults aged 35–59 who had elderly parents in Taiwan.	–	Qualitative research	Co-residence of ageing parents and their married sons is preferred. Other living arrangements are secondary options when the ageing parents cannot live with their married sons. The parents’ most significant factor influencing their decision to live in intergenerational co-residence is their health.
12	Ren and Treiman (2015)	China	Evaluating the impact of ageing parents’ living arrangements on their emotional well-being.	Older people aged 60 and older who lived with adult children.	Elderly respondents living with children under the age of 16.	Cross-sectional study	Living independently with one's spouse is the preferred arrangement from the point of view of emotional well-being, measured by happiness, life satisfaction, and depression. However, living in 3-generation families, with adult children and grandchildren, is equally beneficial, except that widow in such arrangements tends to suffer more significant depression than elder couples living independently.
13	Smits et al. (2010)	The Netherlands	Investigating the extent to which situations and events associated with the support needs of both generations determine co-residence.	Adult children aged 30–40 in 2004.	Adult children over 40 in 2004 and who had only one living parent in 1995. Also, when the children or parents lived in institutions.	Cross-sectional study	There is evidence of the importance of both generations’ support needs, but the needs of the adult children seem more critical than those of the parents, at least for people aged 30-40.
14	Takagi et al. (2007)	Japan	Evaluating the variation in co-residence arrangements in the Japanese context.	Individuals aged 65 years and older who had at least one living child.	Respondents who had missing values on relevant variables that could not reasonably be imputed.	Cross-sectional study	The motives for intergenerational co-residence in Japan are diverse and sometimes deviate from the traditional form. Also, filial piety is a malleable cultural script with different manifestations depending on the contextual characteristics that enable or inhibit the formation of multigenerational households.
15	Teerawichitchainan et al. (2015)	Thailand, Vietnam, and Myanmar	Investigating how intergenerational co-residence, gender of the coresident child, and location of the nearest non-coresident child are associated with the mental health of older parents.	Older adults aged 60 and above with multiple children and at least one non-coresident child.	Older adults in single-child families live with their only child.	Cross-sectional study	Co-residence with a child of a culturally preferred gender improves the psychological health of Vietnamese and Thai elders but with different implications. Meanwhile, for Myanmar, results indicate almost no significant differences in psychological health among older people who live with a child of culturally preferred and non-preferred gender.
16	VanWey and Cebulko (2007)	Brazil	Examining intergenerational co-residence among rural farm families near Santarem, Para, Brazil.	Children of the female household head aged 20 and older.	Adopted children and children under age 20 or had missing information on age.	Cross-sectional study	Children with lower levels of education are more likely to remain on the farm with their parents. Also, marriage makes the daughters leave the house. Conversely, the sons can bring their wives to live in their parent's house.
17	Won and Lee (1999)	South Korea	Determining whether structural factors have similar influences in spite of known cultural differences.	People aged 60 and over with children.	Elderly without a married child.	Cross-sectional study	There are no cultural differences between older people in South Korea and the United States in deciding whether to involve intergenerational co-residence.

Intergenerational co-residence arrangements can stem from diverse determinants, including cultural values that foster the expectation of ageing parents to live with their adult children. Due to this variation, our data interpretation involved a thematic analysis based on the regions of each study’s population to see the dynamic of the factors influencing both generations’ decision to engage in intergenerational co-residence. We divided the regions into four areas: Americas, Europe, East Asia, and Southeast Asia. The determinants factors of intergenerational co-residence based on regions can be seen in Table 2.

Table 2. Intergenerational co-residence based on regions.

Factors	Regions
	Americas	Europe	East Asia	Southeast Asia
Ageing parents
Financial circumstances	Gonzales (2007) Gerber et al. (2019)	Smits et al. (2010) Isengard and Szydlik (2012)	Lee et al. (1995) Won and Lee (1999) Takagi et al. (2007) Johar et al. (2015) Chen (2019)	Domingo and Asis (1995) Johar and Maruyama (2011) Ken and Teerawichitchainan (2015)
Health conditions	Choi (1995) Choi (2003) Gonzales (2007)	Smits et al. (2010) Isengard and Szydlik (2012)	Lee et al. (1995) Johar et al. (2015) Chen (2019)	Domingo and Asis (1995) Johar and Maruyama (2011) Ken and Teerawichitchainan (2015)
Kinship systems	Gonzales (2007)		Lee et al. (1995) Won and Lee (1999) Takagi et al. (2007) Johar et al. (2015)	Domingo and Asis (1995) Teerawichitchainan et al. (2015)
Marital status	Gonzales (2007)	Smits et al. (2010)	Won and Lee (1999) Takagi et al. (2007) Johar et al. (2015) Ren and Treiman (2015) Chen (2019)	Johar and Maruyama (2011)
Level of education	Choi (1995) Gonzales (2007)		Lee et al. (1995) Won and Lee (1999) Johar et al. (2015) Chen (2019)
Number of family members	Gonzales (2007)	Smits et al. (2010) Isengard and Szydlik (2012)	Takagi et al. (2007)	Domingo and Asis (1995) Johar and Maruyama (2011)
Adult Children
Financial circumstances	Choi (2003)	Smits et al. (2010) Isengard and Szydlik (2012)		Domingo and Asis (1995) Johar and Maruyama (2011)
Kinship systems	VanWey and Cebulko (2007)	Smits et al. (2010)	Lee et al. (1995)	Domingo and Asis (1995)
Marital status	Choi (2003) VanWey and Cebulko (2007)	Smits et al. (2010) Isengard and Szydlik (2012)	Johar et al. (2015)	Johar and Maruyama (2011)
Level of education	VanWey and Cebulko (2007)	Isengard and Szydlik (2012)
Number of family members		Smits et al. (2010) Isengard and Szydlik (2012)		Johar and Maruyama (2011)

Financial circumstances

Table 2 shows that financial circumstances are seen as one of the factors motivating intergenerational co-residence in every region. Studies by Gerber et al. (2019) and Gonzales (2007) in the United States found that financial stability can motivate older people to live with their adult children, as well as studies in East Asia (Johar et al., 2015; Takagi et al., 2007; Won & Lee, 1999). Conversely, Smits et al. (2010) revealed that financial strain has become the main determinant for older people living with their adult children in the Netherlands. Lee et al. (1995) also showed a similar result in Taiwan. Parents’ financial stability can be measured through job ownership (Smits et al., 2010), wealth (Johar et al., 2015; Johar & Maruyama, 2011; VanWey & Cebulko, 2007), and home ownership (Domingo & Asis, 1995; Gonzales, 2007; Isengard & Szydlik, 2012). The stability of their financial situation can facilitate the parents in supporting their adult children, especially those children who lose their income resources (Domingo & Asis, 1995; Gerber et al., 2019; Isengard & Szydlik, 2012; Smits et al., 2010; Takagi et al., 2007).

Isengard and Szydlik (2012) investigated intergenerational co-residence in 11 European countries and found that parents’ income had no significant effect on co-residence. However, home ownership can encourage ageing parents and adult children to live together. The size of the parental house appears to correlate positively with the likelihood of adult children residing there. This, combined with soaring housing prices, makes it challenging for the younger generation to attain home ownership. In urban areas, where housing tends to be smaller compared to rural areas, this discourages parents and adult children from living in the same house (Chen, 2019). In contrast, a study in Indonesia showed that homeownership did not affect intergenerational co-residence (Johar & Maruyama, 2011).

From the perspective of adult children, financial strain is the main factor in deciding to co-reside with their parents (Choi, 2003; Domingo & Asis, 1995; Isengard & Szydlik, 2012; Smits et al., 2010). However, no East Asian studies that have mentioned financial strain as the motive for adult children to participate in intergenerational co-residence could be found. Moreover, financially well-off children in Southeast Asia and Europe tend to live independently (Johar & Maruyama, 2011; Smits et al., 2010). However, adult children in Europe who are self-employed or receive ongoing disability benefits tend to engage in an intergenerational co-residence to share their household expenses with their parents (Smits et al., 2010). Similarly, the eldest sons in Japan receive financial help from their parents since older Japanese people endorse the primogenital family system, motivating the children to live with their parents (Johar et al., 2015).

Health condition

On the one hand, most studies in this systematic review found that health deterioration can be a determinant for leading older people to live with their adult children (Choi, 1995, 2003; Gonzales, 2007; Isengard & Szydlik, 2012; Johar et al., 2015; Johar & Maruyama, 2011; Lee et al., 1995). On the other hand, their health conditions can also prevent them from living with their children due to their inability to exchange support (Domingo & Asis, 1995; Gonzales, 2007; Isengard & Szydlik, 2012; Lee et al., 1995). Poor health conditions can prevent older people from assisting their children and engaging in support exchange between generations. A study in the United States showed that ageing parents prefer living in an institution rather than intergenerational co-residence when their health impairment worsens (Choi, 2003). A similar situation was also found to exist in Indonesia, where Johar and Maruyama (2011) revealed that ageing parents were more reluctant to be involved in intergenerational co-residence when their health condition decreased.

However, three studies in the Americas region showed that older people with low ADL/IADL scores were more likely to participate in intergenerational co-residence (Choi, 1995, 2003; Gonzales, 2007). Similarly, Isengard and Szydlik (2012) found that in Europe, older people’s health impacted the decision for them to live with their adult. Likewise, three studies in East Asia (Chen, 2019; Johar et al., 2015; Lee et al., 1995) and two in Southeast Asia (Domingo & Asis, 1995; Ken & Teerawichitchainan, 2015) revealed that health deterioration was one of the main factors that influenced ageing parents to live with their adult children.

No studies were found to directly attribute parents’ health conditions as the trigger for adult children to co-reside with their ageing parents. However, adult children seemed to realise that as their parents age, they become more vulnerable to health deterioration, prompting them to evaluate their ability to provide care. Typically, middle-aged children may feel more reluctant to care for their parents due to their parents’ physical limitations than younger adult children (Choi, 2003; Smits et al., 2010). Further, financially capable children often prefer to care for their parents by recruiting a professional caregiver (Choi, 2003).

Kinship systems

In East Asian countries, such as Taiwan, South Korea, and Japan, there is a cultural value known as filial piety, which emphasizes the responsibility of adult children to care for their ageing parents (Johar et al., 2015; Lee et al., 1995; Takagi et al., 2007; Won & Lee, 1999). This value develops expectations for older people to be taken care of by their children in later life, usually leading to the practice of intergenerational co-residence. Similarly, Gonzales (2007) also found that filial responsibilities were important in determining older adults’ decision to cohabitate with their adult children in the United States. For example, this could occur if a parent's health worsens, leading adult children to feel more responsible for taking care of them as they get older. Additionally, Chen (2019) revealed that parents who are used to living in multigenerational families usually choose to continue living with their family when they get older.

In some countries, filial piety is also associated with the gender of adult children, where sons are attributed to having greater filial responsibilities towards their parents. It can be seen from the studies in South Korea (Won & Lee, 1999), Japan (Takagi et al., 2007), and Vietnam (Teerawichitchainan et al., 2015), where parents choose to live with their sons rather than their daughters. However, research conducted in the Philippines indicated that the nature of the relationship between parents and children is more significant in determining their living arrangements than gender preferences associated with filial piety (Domingo & Asis, 1995). Parents tend to choose the children with whom they feel most comfortable, and this preference often leans towards daughters (Domingo & Asis, 1995; Teerawichitchainan et al., 2015). Conversely, a negative relationship quality between older people and their children can result in a sense of rejection in parents and make them less likely to be involved in intergenerational co-residence (Lee et al., 1995).

Furthermore, adult children across all regions also considered kinship systems in their decisions regarding living arrangements (Domingo & Asis, 1995; Lee et al., 1995; Smits et al., 2010; VanWey & Cebulko, 2007). This indicates that adult children recognize their obligation to care for their parents in later life. One factor that may influence this is the increasing age of parents and the decline in their health, which makes them increasingly reliant on assistance for their daily routines. A study by VanWey and Cebulko (2007) showed that daughters in Brazil were concerned about their parent’s ability to handle housework, so they assisted their parents in completing daily household chores as their parents got older. Domingo and Asis (1995) also mentioned the debt of gratitude as the motive of adult children to co-reside with their parents. These adult children see their parents’ old age as an opportunity to repay the care and support their parents provided in nurturing them.

Marital status

Ageing parents consider their marital status when deciding to participate in intergenerational co-residence. Widowed parents, in particular, are motivated to cohabitate with their children in all regions (Choi, 2003; Johar et al., 2015; Johar & Maruyama, 2011; Ren & Treiman, 2015; Smits et al., 2010; Takagi et al., 2007; Won & Lee, 1999); while Smits et al. (2010) discovered a positive correlation between parental divorce and intergenerational co-residence in the Netherlands. In contrast, divorced parents in the United States prefer to live independently even though they experience health deterioration (Choi, 2003). It is still to be determined why divorced parents are more inclined to live in institutions as their last resort to have better care for their physical limitations. Still, Choi (2003) argued that institutions can provide more adequate care, which may not be available in a home setting.

Research suggests that widowed mothers with a lower level of education tend to live with their children when they get older (Smits et al., 2010; Takagi et al., 2007; Won & Lee, 1999). It is similar to widowed fathers who choose to live in intergenerational co-residence to receive daily assistance, especially in fulfilling the spouses’ roles that were absent after their wives passed away (Johar & Maruyama, 2011). In contrast, older people with spouses may prefer to live independently (Chen, 2019; Won & Lee, 1999). A study in China showed that living with their spouses resulted in better mental health for older people compared to their counterparts who lived in two-generation households (Ren & Treiman, 2015). Likewise, a study from the United States also showed that married parents were more likely to live independently than engage in intergenerational co-residence (Choi, 1995). However, in a sample of Mexican-Americans living in the United States, older adult couples were more likely to invite their children to live with them, as the children could provide better support for the parents, occasionally leading to the phenomenon of boomerang children (Gonzales, 2007). Boomerang children is a term to describe a phenomenon where adult children who have previously left their parental home for extended periods for various reasons return to live with their parents (Casares & White, 2018).

As for adult children, marital status significantly affects their decision to participate in intergenerational co-residence. Many studies in all regions found that married children tend to live independently with their spouses, while unmarried children, especially women, will choose to live with their parents (Choi, 2003; Isengard & Szydlik, 2012; Johar et al., 2015; Johar & Maruyama, 2011; Smits et al., 2010; VanWey & Cebulko, 2007). They will try to maintain their independence until their parents experience a decline in health that requires them to need help in their daily activities (Choi, 2003). Meanwhile, divorced children usually return to their parent's houses to receive financial and psychological support. The presence of young children also leads adult children in Europe and Asia to seek intergenerational co-residence and the assistance of their older parents in parenting their young children (Smits et al., 2010).

Level of education

Another indicator that can protect older people from their vulnerability to engage in intergenerational co-residence is the level of education. Studies in America and East Asia indicate that older adults with higher education levels are less likely to live with their adult children (Chen, 2019; Choi, 1995; Gonzales, 2007). With a high level of education, older people are more likely to have the financial means to support themselves and their families independently (Chen, 2019; Gonzales, 2007). Likewise, a high level of education gives adult children greater opportunities to advance their careers and improve their quality of life, thereby enhancing their economic capabilities (Isengard & Szydlik, 2012). A study in Brazil also showed that male children with low education tend to cohabitate with their parents more often than those with higher levels of education (VanWey & Cebulko, 2007). Hence, a high level of education enables both generations to sustain their independence in their living arrangements.

Number of family members

Some studies showed that the number of children in the family also influences older people’s opportunities to engage in intergenerational co-residence. Studies in the United States, Philippines, Indonesia, and Japan show that older adults who have many children will likely be living with one of their adult children (Domingo & Asis, 1995; Gonzales, 2007; Johar & Maruyama, 2011; Takagi et al., 2007). However, Johar and Maruyama (2011) also showed that older people with one child probably do not receive filial support unless the child has a high level of education or a sound economic foundation. A study conducted across 11 European countries showed that having more children in a family can prevent older people from living with them (Isengard & Szydlik, 2012). This may be due to cramped living conditions or to adult children feeling less responsible for their parents due to the presence of their siblings (Isengard & Szydlik, 2012; Smits et al., 2010).

Discussion

This systematic review has identified factors that influence the inclination of older people and their adult children to participate in intergenerational co-residence across various regions, including America, Europe, East Asia, and Southeast Asia. Financial circumstances, health conditions, the kinship system, marital status, level of education, and the number of family members have emerged as considerations for ageing parents. Similarly, these factors were also considered by adult children, except for health conditions. Together, these factors interplay to determine the co-residence between ageing parents and adult children.

Broadly, across all regions, the decision of parents to reside with their adult children often arises from their desire to support their offspring. Conversely, adult children cohabiting with their parents usually need assistance fulfilling their needs. The factors influencing these two generations to live together are relatively similar. We found that financial circumstances play a significant role. Parents with stable economic conditions are more inclined to offer financial support to their children by cohabiting with them (Gerber et al., 2019; Gonzales, 2007; Johar et al., 2015; Johar & Maruyama, 2011). This aligns with adult children who indeed require assistance from their parents to meet their economic needs (Choi, 2003; Domingo & Asis, 1995; Smits et al., 2010).

Caring for ageing parents toward their adult children is an altruistic behaviour, wherein they express attention and support without anticipating reciprocity (Keene & Batson, 2010). While ageing parents technically no longer bear the responsibility to care for their adult children, globally, many still extend assistance, such as aiding with financial matters, parenting support, and managing household affairs to help the children pursue their careers (Domingo & Asis, 1995; Johar & Maruyama, 2011; Smits et al., 2010). This situation often leads ageing parents to resist the idea of cohabitating with their adult children as they age and their physical abilities decline (Choi, 2003; Johar & Maruyama, 2011). They tend to feel incapable of providing support, which makes them fear becoming burdens rather than a support system for their children.

Indeed, we found that parents’ health conditions were one of the factors that influenced the decision of ageing parents and adult children in all regions to be involved in intergenerational co-residence. However, declining health can also lead parents to resist cohabitation because they feel unable to reciprocate the care provided by their adult children (Choi, 2003). Living together between ageing parents and their adult children undoubtedly facilitates the exchange of support (Zhao, 2023). However, this dynamic can leave parents with health deterioration feeling vulnerable, as they may perceive themselves as trouble for their children due to their inability to reciprocate the care provided by their children (Jennings et al., 2014). Indeed, adult children may want to show their filial piety by caring for their parents in their old age without expecting anything in return (Domingo & Asis, 1995; Zhao, 2023).

We presume that filial piety, traditionally considered a Confucian value prevalent in East Asia, extends beyond this region and is embraced by people in other countries as well, such as the United States (Gonzales, 2007) and the Philippines (Domingo & Asis, 1995), as evidenced by our systematic review findings. This value teaches children a sense of devotion towards their parents, particularly in their old age (Chen et al., 2022). It often manifests through actions such as inviting parents to live with them or the adult child becoming ‘a boomerang child’ to care for their parents. However, intergenerational co-residence is not the sole means of demonstrating devotion to parents. At times, parents cohabitating with their children can sometimes be lonely due to the low quality of the relationship between generations (Chen et al., 2021; Ha & Carr, 2005; Xu et al., 2019). Hence, various studies also highlight that parents consider the quality of their relationship with their children when choosing those who will cohabitate with them (Domingo & Asis, 1995; Lee et al., 1995; Seltzer et al., 2012).

Also, the implementation of filial piety may differ across regions. For example, in East Asia, parents put higher expectations on their sons to take care of them when they are old (Johar et al., 2015; Lee et al., 1995; Takagi et al., 2007; Won & Lee, 1999). Meanwhile, older people in the Philippines, Indonesia, and Thailand are more flexible in choosing their adult children to engage in intergenerational co-residence (Domingo & Asis, 1995; Johar & Maruyama, 2011; Ken & Teerawichitchainan, 2015). They prefer the adult child with whom they have the closest relationship, usually the youngest child (Domingo & Asis, 1995). If we compare between genders, parents typically choose to reside with their daughters rather than their sons (Ken & Teerawichitchainan, 2015; Won & Lee, 1999). They perceive daughters as more caring for fulfilling their daily needs, such as preparing meals, managing their medication, and doing household chores.

In this systematic review, we also observed that residential characteristics can influence parents’ decisions regarding intergenerational co-residence. In regions that are friendly toward older people, ageing parents often have lower expectations of co-residing with their adult children. They feel capable of living independently, thus reducing the need to rely on their adult children for support. However, such policies are not universally implemented across all regions. Only one study in this review was found to evaluate the impact of residential characteristics on intergenerational co-residence (Takagi et al., 2007).

In conducting this systematic review, we used five databases, including CINALH, Embase, PsycINFO, Scopus, and PubMed. These databases were chosen by our literature review, focusing on previous systematic reviews in Geropsychology, particularly those exploring intergenerational relationships between older people and adult children (Gualano et al., 2018; Wang & Lai, 2022; Zhong et al., 2020). To ensure the chosen databases met high-quality control standards, offered a wide range of scholarly articles, were regularly updated, and provided full-text access, consultations were conducted with expert librarians. Although we encountered numerous studies on intergenerational co-residence from diverse global regions, upon closer analysis, it became apparent that this review did not successfully identify studies discussing intergenerational co-residence in specific areas, such as Africa and South Asia.

Study limitation

While this systematic review has achieved its objectives, it is not without certain limitations. First, keywords related to intergenerational co-residence were utilized in literature searches. Despite employing terms established through Medical Subject Headings (MeSH), it remains possible that the six terms used might not encompass all research about intergenerational co-residence. Another limitation is that the review included no African and South Asian studies. Indeed, several African studies were initially identified in the search. However, these primarily focused on intergenerational relationships (Nauck, 2014) or living arrangements in a broader sense (Bongaarts & Zimmer, 2002; McKinnon et al., 2013; Ralston et al., 2019) rather than motivations. That is, these studies did not provide specific insights into intergenerational co-residence determinants, making it challenging to extract relevant factors for inclusion in this systematic review.

Conclusion

This systematic review reveals multiple factors shaping the inclination of older people and adult children to engage in intergenerational co-residence. Beyond the health conditions of ageing parents, considerations such as financial circumstances, kinship systems, marital status, level of education, and number of family members. Moreover, these factors often interact with one another, ultimately determining the outcome of whether to participate in intergenerational co-residence. For example, while health decline may prompt ageing parents to live with their adult children, this may not be the case for mothers, who may choose to live independently due to challenges in supporting their adult children as their health deterioration.

This review has highlighted the complexity and multidimensionality in the decision of ageing parents and adult children to be involved in intergenerational co-residence. The factors identified in this review are interconnected and their dynamics vary depending on the specific context of each population’s region. While similarities exist across regions, the willingness of both generations are also influenced by cultural values and local government policies. Parents’ expectations regarding intergenerational co-residence not only encompass considerations of filial piety but also intersect with government policies related to the care for older people. Therefore, future research should aim to assess these factors and specifically examine their impact on the conditions of both parents and children participating in intergenerational co-residence.

Declaration of contributions of authors

All authors have contributed substantially to designing, analysing, interpreting data and writing this publication.

Disclosure statement

No potential conflict of interest was reported by the author(s).