Objectives
We explored associations between the needs for power, achievement, and affiliation and functional cerebral asymmetries (FCAs), guided by three established hypotheses about the nature of these associations.
Methods
One-hundred-and-seven participants completed picture-story measures of dispositional motives and activity inhibition (AI), a frequent moderator of motive-behavior associations, tasks measuring FCAs (line bisection, chimeric emotional face judgments, turning bias, perceptual and response asymmetries on the Poffenberger task), self-reported laterality preferences (handedness, footedness, ear and eye preference), and interhemispheric interaction (crossed-uncrossed difference). They also completed an experiment manipulating hand contractions (left, right, both, neither) while they worked on a second picture-story motive measure.
Results
Dispositional power motivation was associated with stronger rightward asymmetry and less interhemispheric transfer in high-AI and stronger leftward asymmetry and more interhemispheric transfer in low-AI individuals. For the affiliation motive, findings were fewer and in the opposite direction of those for the power motive. These findings emerged for men, but not for women. Left- or right-hand contractions led to increases in power and achievement motivation, but not affiliation motivation. Only left-hand contractions led to decreased AI.
Conclusions
We discuss these findings in the context of sex-dimorphic organizing and activating effects of steroids on motives and laterality.