The study of the evolution of human traits such as behavioral characteristics and culture is a difficult task. Unlike morphological features, such traits present no direct physical relics of their previous forms, causing extrapolations and educated conjecture to dominate the field of study.
Thus, the argument that cultural evolution possess Darwinian properties, though intriguing, is debatable. In their paper, Mesoudi, Whiten and Laland argue that human cultural evolution can be assessed by the same basic principles cemented by Darwin in his theory of natural selection. The research group defined culture as the collection of beliefs, values and knowledge that was “inherited through social learning”. Elments of culture
However there are certain behaviors integrally tied with culture that depreciate the fitness of an individual. Smoking tobacco and consuming unhealthy foods are both prime examples of cultural activates that lead to a reduction in individual health and reproductive abilities.
Suicidal practices are also an interesting cultural component to assess in terms of Darwinian selection. Seppuku is a term describing the ritual suicide practices of samurai. The ritual disembowelment was viewed as a way to honorably submit to death. Today, Japan has one of the highest suicide rates in the world and culturally, suicide is often portrayed as morally acceptable and honorable, though the recent upsurge in suicide packs has sparked media and public discourse over the proliferation of such practices.
The paper briefly addressed this phenomena, stating that “cultural traits will not necessarily promote the inclusive ﬁtness of the humans expressing them (Cavalli-Sforza and Feldman 1981). In the same way that parasites can manipulate behavior to their own ends (Moore 2002), cultural variants that exhibit high rates of (nonvertical) transmission (such as smoking) can spread whether or not they enhance ﬁtness and promote adaptation in the individuals who adopt them.” Yet it goes no further to address the reasons behind the self induced fitness depreciating behaviors.
For more information regarding the evolution of human cultural variants, please refer to: Mesoudi A., Whiten A., Laland K., 2004. Perspective: Is human cultural evolution Darwinian? Evidence reviewed from the perspective of the Origin of Species. Evolution. 58(1):1-11.