Final answer:
The study suggesting that fathers had more negative interactions with stepchildren versus biological children implies a behavior influenced by natural selection, aligning with evolutionary psychology's perspective on maximizing genetic legacy. The correct answer is option 1.
Step-by-step explanation:
The question posed deals with human behavior and natural selection, suggesting an inquiry into evolutionary psychology. This interdisciplinary field examines how evolutionary principles such as natural selection might have shaped human behaviors that have a genetic basis. To determine if a behavior has evolved due to natural selection, it should be widespread across cultures (indicating a genetic cause) and provide some advantage in terms of survival or reproduction.
Looking at the options provided, the correct one appears to be the study where fathers had significantly more negative interactions with stepchildren versus biological children. This behavior could be seen as an evolutionary strategy to maximize one's genetic legacy by investing more resources and care in one's own offspring, which is aligned with the evolutionary principle of inclusive fitness. This suggests a genetic determinant influencing this social behavior that could be subject to natural selection.
Contrastingly, the options concerning child murder statistics and the popularity of internet memes do not closely relate to evolutionary principles or genetic determinants. In the case of the study of male reed buntings, it presents a parallel in animal behavior that reflects similar evolutionary principles where males contribute more to offspring where they share greater genetic relatedness.
In summary, significant behaviors reflecting evolutionary adaptations are supported by evolutionary biology and can be seen in various aspects such as mating behavior, altruism, and social organization. These behaviors are driven by the inherent need for gene propagation and survival of one's lineage.