Search

Adverse Childhood Experiences (ACEs) are situated as the foundation of a six-tier pyramid, above which rests: (1) disrupted neurodevelopment; (2) social, emotional, and cognitive impairment; (3) adoption of health-risk behaviors; (4) disease, disability, and social problems; and (5) early death. ACEs purportedly initiate a causal sequence of negative developmental, behavioral, social, and cognitive outcomes, culminating in heightened mortality risk. Militating against this causal explanation, life history evolution is herein hypothesized to be the true foundation of any such pyramid. Subsuming ACEs within a life history framework has two broad implications: First, to some extent, ACEs are effectively changed from cause to correlate; second ACEs are seen as markers of strategic life history variation, not markers of dysfunction.

After many waves of out-migration from Africa, different human populations evolved within a great diversity of physical and community ecologies. These ambient ecologies should have at least partially determined the selective pressures that shaped the evolution and geographical distribution of human cognitive abilities across different parts of the world. Three different ecological hypotheses have been advanced to explain human global variation in intelligence: (1) cold winters theory (Lynn, 1991), (2) parasite stress theory (Eppig, Fincher, & Thornhill, 2010), and (3) life history theory (Rushton, 1999, 2000). To examine and summarize the relations among these and other ecological parameters, we divided a sample of 98 national polities for which we had sufficient information into zoogeographical regions (Wallace, 1876; Holt et al., 2013). We selected only those regions for this analysis that were still inhabited mostly by the aboriginal populations that were present there prior to the fifteenth century AD. We found that these zoogeographical regions explained 71.4% of the variance among national polities in our best measure of human cognitive ability, and also more concisely encapsulated the preponderance of the more specific information contained within the sampled set of continuous ecological parameters.

Life history strategy represents individual variation in the degree to which bioenergetic resources are allocated toward growth, maintenance, and reproduction. Individual differences in life history strategies are thought to underlie many of the individual differences studied in Psychology. It was hypothesized that responses on the Sentence Completion Test of Ego Development are partially reflective of an individual’s life history strategy. This hypothesis was tested in three studies, each representing a different level of analysis. The results of Study 1 suggest near unity between ego-level and life history strategy at the conceptual level. In Study 2 a moderate association between rated ego-level and rated life history strategy was found. Additional analyses showed that this association remained when controlling for verbal IQ and that developmental change in each construct was correlated. In Study 3, it was found that responses to the sentence stems could be used directly to assess life history strategy. Combined, the results add to the evidence that responses on projective tests using a sentence stem format are associated with life history strategy. Future research could focus on identifying and constructing sentence stems that provide the maximum information about an individual’s life history strategy.

Size at birth, growth rate, age at sexual maturity, number and size of offspring, and longevity are among the variables studied in life history evolution, a mid-level branch of evolutionary biology. Long-lived, slow maturing, and highly encephalized Homo sapiens, though skewed as a group towards the very slow end of the spectrum, nevertheless show some life history variation; variation which may relate to, and to some extent explain, personality variation. When applied to extant personality disorders, the risk-taking, boldness, and impulsivity of psychopathy is explained as a fast life history strategy. Herein, it is argued that the highly heritable obsessive-compulsive personality disorder (OCPD), opposite psychopathy, is a slow life history strategy. Both OCPD and slow life history strategists exhibit anxiety and harm avoidance, risk and loss aversion, future-oriented thought and time urgency, delayed gratification, and conscientious labor and fidelity. In addition to a host of compelling correlations, the preponderance of intrinsic over extrinsic mortality that explains the evolution of slow life histories is precisely that which has been described in an ecological etiology that explains OCPD as a product of post-migration evolution from Africa into Eurasia.

The obsessive-compulsive personality pattern of orderliness, parsimony, and obstinacy was first described and explained by Sigmund Freud. Freud’s description was sound, but his explanation was flawed. Further still, no extant etiology, psychoanalytic or otherwise, convincingly accounts for the existence, and intergenerational perpetuation, of obsessive character. Thus, herein is presented a new etiology; an evolutionary etiology that describes obsessive personality, not as a disorder, but as an extreme strategy whose imbalance is a product of post-dispersal evolution. Migration into northerly latitudes brought about a relative release from biotic selective pressures, such as conflict and conspecific competition, and a corresponding increase in abiotic selective pressures, such as cold and seasonal scarcity. Features such as (1) future-oriented thought, (2) parsimoniousness, and (3) compulsive conscientiousness become both viable and intelligible as a temperamental consequence of struggling more exclusively with the elements. After using comparative animal data to demonstrate their biogeographical distribution, the human distribution of these three traits is also shown to be concentrated within northerly latitudes.