Handedness and Motivational Asymmetries as Precursors to Personality and Political Ideology

Abstract

Recent research and theorizing in political psychology have favored a social cognitive model of political ideology, in which conservative attitudes arise from a need for psychological security in a threatening world. In keeping with this worldview, conservatism has been linked to a greater tendency to withdraw from threats, while liberalism has been associated with approach-related behaviors. However, several conflicting findings from other research streams belie such straightforward explanations, and the relative dearth of neural evidence makes it difficult to trace political approach and withdrawal motivations back to their roots in the brain. Connecting these motivational tendencies to neural activity would help establish a more nuanced causal model of political ideology, but doing so first requires a meaningful explanation grounded in theory. Parallel findings in another area of research suggest one such possibility. Big Five personality domains demonstrate relationships with measures of approach and withdrawal motivation, while maladaptive personality traits appear to show similar motivational connections. Importantly for purposes of theory development, the measures of approach and withdrawal associated with the Big Five have also been independently associated with activity in specific brain areas. EEG studies have shown that approach motivation corresponds to increased left-hemisphere activation in frontal areas whereas withdrawal motivation relates to greater frontal right-hemisphere activation. Therefore, cerebral motivational asymmetries present a plausible mechanism by which brain activity could influence levels of approach and withdrawal motivation, which in turn could lead to differences in personality and political ideology. Since adequately powered neuroimaging studies are often financially and logistically prohibitive, an additional benefit of this model is that it can be tested using a proxy variable that also demonstrates unique associations with the variables of interest. Handedness has long been tied to hemispheric lateralization, likely due to shared genetic influences, with empirical evidence supporting a relationship between left- and inconsistent-handedness and increased right-hemisphere activity. Right- and consistent-handedness, on the other hand, appear to be related to greater left-hemisphere activation. Using handedness in lieu of hemispheric activation, while not without its drawbacks, made it possible to indirectly test the aforementioned model in the present study in a larger online sample (N = 499) and to investigate how handedness, an often-overlooked variable in most areas of psychology, related to personality and political constructs. Participants from the University of Minnesota and Amazon’s Mechanical Turk completed a series of online survey measures to address the broader question of whether approach and withdrawal motivation explain any observed relationships between handedness and personality and political ideology. Additionally, the current study tested a variety of relationships between variables that are rarely included in the same study (e.g., recently developed measures of maladaptive personality and political ideology). Another aim of the present study was to explore methodological issues that have plagued the various literatures it connects, such as the artificial dichotomization of handedness scores and differing theoretical and operational definitions of approach and withdrawal motivation. In an effort to address divergent results from questionnaire and behavioral measures in the literature, I also designed an approach/avoidance task for inclusion in the study. Results indicated that approach and withdrawal motivation may partially account for relationships between handedness and personality and political ideology, although additional research is needed to clarify unexpected findings. Results from the present study are interpreted in terms of conflicting theories from the political, cognitive, and personality literatures, and future research is proposed to address lingering uncertainties in this domain of study.