Culture sets us apart: Cultural evolution as a solution to the challenges of social relationships

Humans are a social species, relying on a complex network of long-term relationships and cooperation to tackle ecological problems such as obtaining resources, safety and procreation. This rich sociality is as demanding as it is rewarding; while affiliation and status are intrinsically valuable, securing these benefits requires significant cognitive effort, material investment, compromise, and vigilance. Common views of cultural evolution and innovations often frame social interactions either as a vehicle to transmit knowledge across generations, or as a cooperation problem to be solved. I propose that culture evolves to directly address the challenges and costs inherent in social relationships. Cultural innovations help facilitate social interactions by making them more predictable and regular, and promoting independence and flexibility. Predictability can be achieved through centralized social events and experiences, such as rituals and stories, and through institutions and norms. Independence is promoted by technologies that enable individuals to carry out tasks on their own, and by substituting some of the benefits associated with social relationships. In all cases cultural innovations success can be evaluated by the way they meet the needs and offset the costs of social interactions. This view can explain the adaptive interactions between cultural innovations and social relationships.