Monetary incentive, age, and cognition.

Area of Science:

• Psychology
• Behavioral Science
• Research Methodology

Background:

• Volunteer participant characteristics can influence study outcomes.
• Previous research suggests potential cohort differences beyond age.

Purpose of the Study:

• To investigate if a monetary incentive ($10.00) affects volunteer participant characteristics.
• To compare personality and intelligence factors between incentivized and non-incentivized groups.

Main Methods:

• Compared 2466 potential subjects on willingness to participate.
• Assessed 591 tested subjects on Primary Mental Abilities Test, Test of Behavioral Rigidity, and Cattell's 16 PF.
• Analyzed intercorrelation matrices for differences between incentive conditions.

Main Results:

• No significant differences were found in willingness to participate or on intelligence/personality test scores.
• Differences were observed in intercorrelation matrices for women on Cattell's 16 PF (Form B) between incentive groups.
• Monetary incentives did not significantly alter sample characteristics regarding age or sex.

Conclusions:

• Monetary incentives have a limited impact on the general characteristics of volunteer research samples.
• Researchers can generally use modest financial incentives without compromising sample representativeness for most measures.
• Further investigation may be needed for specific psychological measures, particularly concerning gender differences in intercorrelation patterns.