Paper short abstract:

I argue that hairloss in hominins may have precipitated nocturnal fire use, which would also facilitate cooking. Due to the requirement for delayed gratification in cooking, this could have started gradual evolution of temporal inhibition, a pre-requisite for many culturally-inherited technologies.

Paper long abstract:

Hairloss boosts the ability to shed heat efficiently via sweating, allowing the occupation of high temperature areas and spread of hominins to low-altitude / semi-arid environments, plus greater speed of locomotion and daytime activity without overheating (and thus increased maximum day-range and better access to resources, facilitating larger groups and higher technological complexity). Despite the advantages of hairlessness, heat loss overnight would have been prohibitively costly. Fire use would have been one possible solution to this problem. Fire also facilitates cooking, reducing the cost of digestion and disease burden of food. However, cooking assumes bypassing the fear of fire and delayed gratification of food consumption during the cooking process (far from trivial, as many animals have a strong drive to eat food immediately to satisfy hunger). This offers a pathway towards the evolution of temporal inhibition that could provide a psychological basis for the ability to both handle food and wait while it cooks. Most culturally inherited human technologies share a similar temporal structure to cooking, tending to require some initial investment, followed by a lengthy wait that requires temporal inhibition. Cooking might have provided an evolutionary pathway towards the emergence of abilities that allow complicated economic technologies prevalent today. Increased climatic variation would have put a mid- to high-latitude living hominin under pressure that might have triggered the abandonment of inherited fear of fire, as well as starting a cycle of hairloss in hot periods, increased fire use during cold periods, and gradual evolution of temporal inhibition.