D. T. O'Brien

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Handgrip strength (HGS) is highly heritable and a good overall measure of strength and muscle function. Indicative of blood testosterone levels and fat-free body mass, HGS is also highly sexually dimorphic. Recent psychological research shows that HGS is correlated with a number of social variables, but only in males. We conducted three studies to further(More)
Prosociality is a fundamental theme in all branches of the human behavioral sciences. Evolutionary theory sets an even broader stage by examining prosociality in all species, including the distinctive human capacity to cooperate in large groups of unrelated individuals. We use evolutionary theory to investigate human prosociality at the scale of a small(More)
All communities have common resources that are vulnerable to selfish motives. The current paper explores this challenge in the specific case of the urban commons, defined as the public spaces and scenery of city neighborhoods. A theoretical model differentiates between individual incentives and social incentives for caring for the commons. The quality of a(More)
It has been suggested that the use of intrasexual aggression is a form of competition associated with reproductive opportunities. Here the authors investigated the relationship between retrospective dating and flirting behavior and peer aggression and victimization during middle and high school. Results indicate that the use of peer aggression was(More)
When entering an unfamiliar neighborhood, adaptive social decisions are dependent on an accurate assessment of the local safety. Studies of cities have shown that the maintenance of physical structures is correlated with the strength of ties between neighbors, which in turn is responsible for the crime level. Thus it should be theoretically possible to(More)
The current study presents a case in which adolescent prosociality is lower in neighborhoods with greater physical disorder. Current theory provides two interpretations for such a pattern: (1) that disorder signals a threatening environment and discourages prosociality ("broken windows theory"); (2) that disorder and low prosociality are both symptoms of a(More)
Much research has focused on physical disorder in urban neighborhoods as evidence that the community does not maintain local norms and spaces. Little attention has been paid to the opposite: indicators of proactive investment in the neighborhood's upkeep. This manuscript presents a methodology that translates a database of approved building permits into an(More)
Neighborhood social dynamics have been shown to impact behavioral development in residents, including levels of prosociality (i.e. positive social behavior). This study explores whether residential moves to neighborhoods with different social dynamics can influence further prosocial development. Prosociality, five domains of social support, and residential(More)
STUDY OBJECTIVES A chinstrap is potentially useful to reduce unintentional air leak by preventing mouth opening during PAP treatment. This study examines whether the addition of a chinstrap to PAP therapy has any effect on adherence, nightly duration of use, air leak, and residual AHI. METHODS This was a retrospective study performed at an AASM-accredited(More)
This past June Kotabe (2014) presented the World is Random (WIR) model for disorder perception. He argued that it can explain phenomena across domains and multiple levels of analysis, most importantly the dynamics articulated by the popular sociological theory of “broken windows” (BWT). There are two critical problems with this claim. First, Kotabe makes a(More)