Abstract
The MACH–IV was investigated (N = 528) with item response theory to elucidate its psychometric properties and suggest a trimmed version, the MACH*. The core content of the MACH–IV seemed to be cynicism/misanthropy and the MACH* was formed from the 5 most informative and precise MACH–IV items. The MACH* showed good internal consistency and construct and criterion validity comparable to the MACH–IV. The MACH–IV and MACH* measure most precisely at average to above average levels of Machiavellianism. Implications for theory and measurement of Machiavellianism are discussed.