Is synaesthesia a dominantly female trait?

Figures & data

TABLE 1 Shows the number of confirmed male (M) and female (F) grapheme-color synaesthetes found in our total sample of 3893 subjects (F = 2135; M = 1758). The prevalences are shown in brackets, with the female: male ratio beneath. This is done twice according to two different cut-off for synaesthesia (a score of 1 vs. 1.43 in The Synesthesia Battery) and twice according to two different definitions of grapheme-color synaesthesia (having colored letters AND/OR digits, vs. colored letters AND digits).

Coloured triggers	Sex & ratio	Battery cut-off at 1	Battery cut-off at 1.43
Letters AND/OR digits	F	33 (1.55%)	55 (2.58%)
	M	21 (1.19%)	39 (2.22%
	F + M	=54 (1.39%)	=94 (2.42%)
	Ratio F:M	1.3:1	1.2:1
Letters AND digits	F	12 (0.56%)	23 (1.08%)
	M	11 (0.63%)	19 (1.08%)
	F + M	=23 (0.59%)	=42 (1.08%)
	Ratio F:M	0.89: 1	1:1