The Conversation offers this interesting item titled “Macaque monkeys shrink their social networks as they age,” adding the byline “new research suggests evolutionary roots of a pattern seen in elderly people, too.”
Research on 200 macaques living on an islandoff of Puerto Rico revealed that the impetus to reduce social contacts suggested an unconscious motive of propmoting health and avoiding disease in aging. The chief remaining contacts as the monkeys grew older were family and friends.