Friendship is the single most important factor influencing our health, well-being, and
happiness. Creating and maintaining friendships is, however, extremely costly, in terms of …

The question as to why primates have evolved unusually large brains has received much
attention, with many alternative proposals all supported by evidence. We review the main …

Activity level (the proportion of time that animals spend active) is a behavioural and
ecological metric that can provide an indicator of energetics, foraging effort and exposure to …

Moving in synchrony leads to cooperative behavior and feelings of social closeness, and
dance (involving synchronization to others and music) may cause social bonding, possibly …

Many animals regulate their activity over a 24-h sleep–wake cycle, concentrating their peak
periods of activity to coincide with the hours of daylight, darkness, or twilight, or using …

Psychological studies of relationships tend to focus on specific types of close personal
relationships (romantic, parent–offspring, friendship) and examine characteristics of both the …

Humans have developed a number of specific mechanisms that allow us to maintain much
larger social networks than would be expected given our brain size. For our primate cousins …

The human social world is orders of magnitude smaller than our highly urbanized world
might lead us to suppose. In addition, human social networks have a very distinct fractal …

The effect of Internet use on social relationships is still a matter of intense debate. This study
examined the relationships between use of social media (instant messaging and social …

Primate societies are characterized by bonded social relationships of a kind that are rare in
other mammal taxa. These bonded relationships, which provide the basis for coalitions, are …