Most children tend to describe friendship in terms of things like sharing, and children are more likely to share with someone they consider to be a friend.
My edits/additions:
Recent work on friendship in young children investigated the cues they use to infer friendship. Young children use cues such as sharing resources, like snacks[1], and sharing secrets[2], especially in older adolescents, to determine friendship status. When comparing cues of similarity in food preference or gender, propinquity, and loyalty in adolescent children, younger children rely on similarity in gender/food preferences but more so propinquity to infer friendship while older adolescents rely heavily on propinquity to infer friendship[3].
Forming and maintaining friendships often requires time and effort.
Friendships are foremost formed by choice, typically on the basis that the parties involved admire each other on an intimate level, and enjoy commonality and socializing
My additions:
Given that friendships provide people with many mental, social, and health benefits[4], people should want to associate with and form lasting relationships with people who can provide the benefits they need. Thus, people have specific friendship preferences for the types of behaviors and traits that are associated with these benefits[5]. Recent work on friendship preferences shows that while there is much overlap between men and women for the traits they prefer in close same-gender friends (e.g., being prioritized over other friends, friends with varied knowledge/skills), there are some differences: women compared to men had greater preference for emotional support, emotional disclosure, and emotional reassurance, while men compared to women had greater preference for friends that offer opportunities for accruing status, boosting their reputation, and will provide physical aid[6].
Interspecies
editSee also: Ethology, Altruism in animals, and Sociobiology
Friendship is found among animals of higher intelligence, such as higher mammals and some birds. Cross-species friendships are common between humans and domestic animals, such as a pet snake. Cross-species friendships may also occur between two non-human animals, such as dogs and cats.
My edits/additions:
Non-human friendships
There is ample comparative animal research on the existence of friendships, or the existence of similar forms of relationships, in animals. The function of these relationships in non-human animals appears to primarily be for forming and solidifying alliances for a wide range of fitness and survival reasons[7]. Across a range of non-human animal species, alliances are formed for protection[7], competition over reproductive access to receptive mates[8], as means to seek social comfort[9], solidify social bonds[10], and to thwart diseases[11]. An expansive meta-analysis examining grooming behaviors in 14 different primate species found that grooming behaviors elicit different types of benefit exchanges, such as support and aid for future intra-species conflicts[12]. Male bottlenose dolphins use synchronous surfacing to determine membership of other potential male allies[13] while female bottlenose dolphins use gentle contact behaviors (i.e., touching behaviors) with other females in response to harassment from males[14]. Female spotted hyenas, whose groups follow a very strict dominance hierarchy, form alliances (i.e., coalitionary bonds) to move up the dominance hierarchy by usurping a hyena of higher dominance rank[15]. Feral female horses develop alliances with other female horses to avoid harassment from male horses and these alliances aid in increasing their offspring’s chances of survival[16].
I'd like to add a subsection after the Culture subsection for Evolutionary Approaches to friendship. My edits and additions:
Evolutionary approach
Evolutionary approaches to understanding friendship focus primarily on its function. In other words, what does friendship do for individuals, how does it work psychologically, and how do these processes affect people’s actual behavior. Within this field, there are multiple proposed theories or perspectives about the function of forming friendships and making friends. One is the theory of Reciprocal Altruism which provides an explanation as to why individuals make friends with un-related others. It argues that friendship allows people to exchange benefits with each other and keep track of these exchanges in order to avoid exchanging benefits with a poor cooperator, or someone who will take benefits without giving any in return[17]. Another perspective likens friendships to insurance investments and argues that people should keep the following factors in mind when deciding to invest into forming a friendship with another person: an individual should be able to discern whether the potential friend will be willing to help them back in the future, if the potential friend is in the position to help them in the future, and if the partnership is worth continuing or not, especially when many other potential friendships can be made[18]. These factors will determine whether forming a friendship with someone will be beneficial or not. Another explanation for the function of friendships is called the Alliance Hypothesis[19] which argues that the function of friendships is to acquire alliances for future conflicts or disputes. The Alliance Hypothesis states that conflicts can be won if and only if one side is able to acquire more allies than the competing side, all else equal, so individuals should be able to increase their odds of winning the conflict if they are able to recruit more alliances to their side[19]. Choosing your allies can be very important and there exists a variety of methods in deciding allies such as bandwagoning or choosing an ally that is loyal and will come to your aid in the future conflicts[20]. Thus, individuals should form alliances (i.e., friendships) with people that ranks themselves higher than other allies/friends. It is relative rank (i.e., where the self ranks among all other individuals) that is the most important contributing factor when deciding who is a loyal ally and friend[20].
I'd make another subsection here called Friendship Jealousy. My additions:
Friendship jealousy
Friendship jealousy is also an important topic in evolutionary approaches to friendship. Jealousy is an emotion that is often studied in the context of romantic and sexual relationships. However, individuals also feel jealous when it comes to potentially losing valued friendships. Friendship jealousy acts as an alert to the self that a close friends’ other friends may be a threat to the self’s relationship with that close friend[20] which motivates the self to enact behaviors that prevent the close friend from further developing better relationships with their other friends[5]. A recent large-scale study found that friendship jealousy is activated by the potential loss of a friend by another person, is highly attuned to the feeling or thoughts of being replaced, and that the closer or more valued that friendship is, the more friendship jealousy someone will feel[21]. Men and women also tend to express different levels of friendship jealousy depending on the person who is attempting to replace them in the friendship, such that women compared to men expressed more jealousy over the potential loss of a best-friend to another woman[22].
- ^ DeJesus, Jasmine M.; Rhodes, Marjorie; Kinzler, Katherine D. (2013-10-07). "Evaluations Versus Expectations: Children's Divergent Beliefs About Resource Distribution". Cognitive Science. 38 (1): 178–193. doi:10.1111/cogs.12093. ISSN 0364-0213.
- ^ Liberman, Zoe; Shaw, Alex (2018-11). "Secret to friendship: Children make inferences about friendship based on secret sharing". Developmental Psychology. 54 (11): 2139–2151. doi:10.1037/dev0000603. ISSN 1939-0599.
{{cite journal}}: Check date values in:|date=(help) - ^ Liberman, Zoe; Shaw, Alex (2019-08). "Children use similarity, propinquity, and loyalty to predict which people are friends". Journal of Experimental Child Psychology. 184: 1–17. doi:10.1016/j.jecp.2019.03.002. ISSN 0022-0965.
{{cite journal}}: Check date values in:|date=(help) - ^ Dunbar, R.I.M. (2018-01). "The Anatomy of Friendship". Trends in Cognitive Sciences. 22 (1): 32–51. doi:10.1016/j.tics.2017.10.004. ISSN 1364-6613.
{{cite journal}}: Check date values in:|date=(help) - ^ a b Tooby, J; Cosmides, Leda (1996). Friendship and the banker's paradox: Other pathways to the evolution of adaptations for altruism. Oxford University Press.
- ^ Williams, Keelah E.G.; Krems, Jaimie Arona; Ayers, Jessica D.; Rankin, Ashley M. (2022-01). "Sex differences in friendship preferences". Evolution and Human Behavior. 43 (1): 44–52. doi:10.1016/j.evolhumbehav.2021.09.003. ISSN 1090-5138.
{{cite journal}}: Check date values in:|date=(help) - ^ a b Hemelrijk, Charlotte K.; Steinhauser, Jutta (2007), "15 Cooperation, Coalition, and Alliances", Handbook of Paleoanthropology, Berlin, Heidelberg: Springer Berlin Heidelberg, pp. 1321–1346, retrieved 2023-11-26
- ^ Hemelrijk, Charlotte K.; Luteijn, Madelein (1998-03-23). "Philopatry, male presence and grooming reciprocation among female primates: a comparative perspective". Behavioral Ecology and Sociobiology. 42 (3): 207–215. doi:10.1007/s002650050432. ISSN 0340-5443.
- ^ Shutt, Kathryn; MacLarnon, Ann; Heistermann, Michael; Semple, Stuart (2007-02-27). "Grooming in Barbary macaques: better to give than to receive?". Biology Letters. 3 (3): 231–233. doi:10.1098/rsbl.2007.0052. ISSN 1744-9561.
- ^ Silk, Joan B. (2002-10). "The Form and Function of Reconciliation in Primates". Annual Review of Anthropology. 31 (1): 21–44. doi:10.1146/annurev.anthro.31.032902.101743. ISSN 0084-6570.
{{cite journal}}: Check date values in:|date=(help) - ^ Zamma, Koichiro (2002-03). "Grooming site preferences determined by lice infection among Japanese macaques in Arashiyama". Primates. 43 (1): 41–49. doi:10.1007/bf02629575. ISSN 0032-8332.
{{cite journal}}: Check date values in:|date=(help) - ^ Schino, Gabriele (2006-10-03). "Grooming and agonistic support: a meta-analysis of primate reciprocal altruism". Behavioral Ecology. 18 (1): 115–120. doi:10.1093/beheco/arl045. ISSN 1465-7279.
- ^ Connor, Richard C.; Smolker, Rachel; Bejder, Lars (2006-12). "Synchrony, social behaviour and alliance affiliation in Indian Ocean bottlenose dolphins, Tursiops aduncus". Animal Behaviour. 72 (6): 1371–1378. doi:10.1016/j.anbehav.2006.03.014. ISSN 0003-3472.
{{cite journal}}: Check date values in:|date=(help) - ^ Connor, Richard; Mann, Janet; Watson‐Capps, Jana (2006-06-09). "A Sex‐Specific Affiliative Contact Behavior in Indian Ocean Bottlenose Dolphins, Tursiops sp". Ethology. 112 (7): 631–638. doi:10.1111/j.1439-0310.2006.01203.x. ISSN 0179-1613.
- ^ Strauss, Eli D.; Holekamp, Kay E. (2019-03-11). "Social alliances improve rank and fitness in convention-based societies". Proceedings of the National Academy of Sciences. 116 (18): 8919–8924. doi:10.1073/pnas.1810384116. ISSN 0027-8424.
- ^ Cameron, Elissa Z.; Setsaas, Trine H.; Linklater, Wayne L. (2009-08-18). "Social bonds between unrelated females increase reproductive success in feral horses". Proceedings of the National Academy of Sciences. 106 (33): 13850–13853. doi:10.1073/pnas.0900639106. ISSN 0027-8424.
- ^ Trivers, Robert L. (1971-03). "The Evolution of Reciprocal Altruism". The Quarterly Review of Biology. 46 (1): 35–57. doi:10.1086/406755. ISSN 0033-5770.
{{cite journal}}: Check date values in:|date=(help) - ^ Burkett, Brandy; Cosmides, Leda; Bugental, Daphne (2007). "Jealousy, friendship, and the banker's paradox". PsycEXTRA Dataset. Retrieved 2023-11-26.
- ^ a b DeScioli, Peter; Kurzban, Robert (2009-06-03). "The Alliance Hypothesis for Human Friendship". PLoS ONE. 4 (6): e5802. doi:10.1371/journal.pone.0005802. ISSN 1932-6203.
{{cite journal}}: CS1 maint: unflagged free DOI (link) - ^ a b c DeScioli, Peter; Kurzban, Robert; Koch, Elizabeth N.; Liben-Nowell, David (2011-01). "Best Friends". Perspectives on Psychological Science. 6 (1): 6–8. doi:10.1177/1745691610393979. ISSN 1745-6916.
{{cite journal}}: Check date values in:|date=(help) - ^ Krems, Jaimie; Williams, Keelah; Kenrick, Douglas; Aktipis, Athena (2020-04-28). "Friendship jealousy: One tool for maintaining friendships in the face of third-party threats?". dx.doi.org. Retrieved 2023-11-26.
- ^ Krems, Jaimie Arona; Williams, Keelah E.G.; Merrie, Laureon A.; Kenrick, Douglas T.; Aktipis, Athena (2022-03). "Sex (similarities and) differences in friendship jealousy". Evolution and Human Behavior. 43 (2): 97–106. doi:10.1016/j.evolhumbehav.2021.11.005. ISSN 1090-5138.
{{cite journal}}: Check date values in:|date=(help)