Editing Signalling theory (section)

=== Costly signalling in hunting ===

[[File:Kalina hunter gatherer.jpg|thumb|left|A male hunter and a female gatherer of the [[Kalina people|Kali'na people]] of Guyana, drawn by [[Pierre Barrère]] in 1743. Generous sharing by male hunters may serve as a "costly signal", helping them to acquire mates.]]

Large game hunting has been studied extensively as a signal of men's willingness to take physical risks, as well as showcase strength and coordination.{{sfn|Bliege Bird|Smith|Bird|2001}}{{sfn|Gurven|Hill|2009}}{{sfn|Hawkes|1990}}{{sfn|Wiessner|2002}} Costly signalling theory is a useful tool for understanding food sharing among [[hunter gatherers]] because it can be applied to situations in which [[Reciprocity (cultural anthropology)|delayed reciprocity]] is not a viable explanation.{{sfn|Bliege Bird|Bird|1997}}{{sfn|Gurven|Hill|Hurtado|Lyles|2000}}{{sfn|Hawkes|1993}} Instances that are particularly inconsistent with the delayed reciprocity hypothesis are those in which a hunter shares his kill indiscriminately with all members of a large group.{{sfn|Wiessner|1996}} In these situations, the individuals sharing meat have no control over whether or not their generosity will be reciprocated, and [[Free rider problem|free riding]] becomes an attractive strategy for those receiving meat. Free riders are people who reap the benefits of group-living without contributing to its maintenance.{{sfn|Barrett|Dunbar|Lycett|2002}} Costly signalling theory can fill some of the gaps left by the delayed reciprocity hypothesis.{{sfn|Sosis|2000b}}{{sfn|Smith|Bliege Bird|2000}} Hawkes has suggested that men target large game and publicly share meat to draw social attention or to show off.{{sfn|Hawkes|1991}}{{sfn|Hawkes|1993}} Such display and the resulting favorable attention can improve a hunter's reputation by providing information about his phenotypic quality. High quality signallers are more successful in acquiring mates and allies. Thus, costly signalling theory can explain apparently wasteful and [[altruism|altruistic]] behaviour.{{sfn|Zahavi|1975}}{{sfn|Grafen|1990}}{{sfn|Smith|Bliege Bird|2000}}{{sfn|Johnstone|1995}}{{sfn|Johnstone|1997}}{{sfn|Zahavi|1975}}{{sfn|Zahavi|1977}}

In order to be effective, costly signals must fulfill specific criteria.{{sfn|Zahavi|1975}}{{sfn|Bliege Bird|Smith|Bird|2001}}{{sfn|Hawkes|Bliege Bird|2002}} Firstly, signallers must incur different levels of cost and benefit for signalling behaviour. Secondly, costs and benefits must reflect the signallers' [[phenotype|phenotypic]] quality. Thirdly, the information provided by a signal should be directed at and accessible to an audience. A receiver can be anyone who stands to benefit from information the signaller is sending, such as potential mates, allies, or competitors. Honesty is guaranteed when only individuals of high quality can pay the (high) costs of signalling. Hence, [[Handicap principle|costly signals]] make it impossible for low-quality individuals to fake a signal and fool a receiver.{{sfn|Zahavi|1975}}{{sfn|Bliege Bird|Smith|Bird|2001}}{{sfn|Hawkes|Bliege Bird|2002}}
 
Bliege Bird et al. observed turtle hunting and spear fishing patterns in a [[Meriam people|Meriam]] community in the [[Torres Strait]] of Australia, publishing their findings in 2001.<ref>{{cite journal | url=https://academic.oup.com/beheco/article/14/1/116/209182 | doi=10.1093/beheco/14.1.116 | title=The benefits of costly signaling: Meriam turtle hunters | year=2003 | last1=Smith | first1=E. A. | journal=Behavioral Ecology | volume=14 | pages=116–126 | doi-access=free }}</ref><ref>{{Cite thesis |last=Grayson |first=Jillian |title=Characteristics of traditional dugong and green turtle fisheries in Torres Strait: opportunities for management |date=2011 |publisher=James Cook University {{!}} Australia |url=https://researchonline.jcu.edu.au/29585/ |doi=10.25903/r8eh-n255}}</ref> Here, only some Meriam men were able to accumulate high caloric gains for the amount of time spent turtle hunting or spear fishing (reaching a threshold measured in kcal/h). Since a daily catch of fish is carried home by hand and turtles are frequently served at large feasts, members of the community know which men most reliably brought them turtle meat and fish. Thus, turtle hunting qualifies as a costly signal. Furthermore, turtle hunting and spear fishing are actually less productive (in kcal/h) than foraging for shellfish, where success depends only on the amount of time dedicated to searching, so shellfish foraging is a poor signal of skill or strength. This suggests that energetic gains are not the primary reason men take part in turtle hunting and spear fishing.{{sfn|Bliege Bird|Smith|Bird|2001}} A follow-up study found that successful Meriam hunters do experience greater social benefits and reproductive success than less skilled hunters.{{sfn|Smith|Bliege Bird|Bird|2002}}

The [[Hadza people]] of [[Tanzania]] also share food, possibly to gain in reputation.{{sfn|Marlowe|2010}} Hunters cannot be sharing meat mainly to provision their families or to gain reciprocal benefits, as teenage boys often give away their meat even though they do not yet have wives or children, so costly signalling of their qualities is the likely explanation.{{sfn|Hawkes|O'Connell|Blurton_Jones|2001}} These qualities include good eyesight, coordination, strength, knowledge, endurance, or bravery. Hadza hunters more often pair with highly fertile, hard-working wives than non-hunters.{{sfn|Hawkes|Bliege Bird|2002}} A woman benefits from mating with a man who possesses such qualities as her children will most likely inherit qualities that increase fitness and survivorship. She may also benefit from her husband's high social status. Thus, hunting is an honest and costly signal of phenotypic quality.{{sfn|Smith|Bliege Bird|2000}}{{sfn|Hawkes|O'Connell|Blurton Jones|2001}} [[Frank Marlowe|Frank W. Marlowe]]'s ''The Hadza: Hunter-Gatherers of Tanzania'' showed that this data confirms that this is also true within the Hadza, based on the documentation on the [[!Kung]], in Megan Biesele's book on !Kung folklore, ''Women Like Meat''.

Among the men of [[Ifaluk]] atoll, costly signalling theory can also explain why men torch fish.{{sfn|Sosis|2000a}}<ref>{{Cite journal |last=Sosis |first=Richard |date=July 2000 |title=Costly signaling and torch fishing on Ifaluk atoll |url=https://linkinghub.elsevier.com/retrieve/pii/S1090513800000301 |journal=Evolution and Human Behavior |language=en |volume=21 |issue=4 |pages=223–244 |doi=10.1016/S1090-5138(00)00030-1|pmid=10899476 |bibcode=2000EHumB..21..223S |url-access=subscription }}</ref> Torch fishing is a ritualized method of fishing on Ifaluk whereby men use torches made from dried coconut fronds to catch large [[Dogtooth tuna|dog-toothed tuna]]. Preparation for torch fishing requires significant time investments and involves a great deal of organization. Due to the time and energetic costs of preparation, torch fishing results in net caloric losses for fishers. Therefore, torch fishing is a handicap that serves to signal men's productivity.{{sfn|Sosis|2000a}} Torch fishing is the most advertised fishing occupation on Ifaluk. Women and others usually spend time observing the canoes as they sail beyond the reef. Also, local rituals help to broadcast information about which fishers are successful and enhance fishers' reputations during the torch fishing season. Several ritual behaviors and dietary constraints clearly distinguish torch fishers from other men. First, males are only permitted to torch fish if they participate on the first day of the fishing season. The community is well informed as to who participates on this day, and can easily identify the torch fishers. Second, torch fishers receive all of their meals at the canoe house and are prohibited from eating certain foods. People frequently discuss the qualities of torch fishermen. On Ifaluk, women claim that they are looking for hard-working mates.{{sfn|Sosis|Feldstein|Hill|1998}} With the distinct sexual division of labor on Ifaluk, industriousness is a highly valued characteristic in males.{{sfn|Sosis|1997}} Torch fishing thus provides women with reliable information on the work ethic of prospective mates, which makes it an honest costly signal.{{sfn|Smith|Bliege Bird|2000}}

In many human cases, a strong reputation built through costly signalling enhances a man's social status over the statuses of men who signal less successfully.{{sfn|Wiessner|1996}}{{sfn|Kelly|1995}}{{sfn|Dowling|1968}} Among northern [[Kalahari]] foraging groups, traditional hunters usually capture a maximum of two or three antelopes per year.{{sfn|Lee|1979}} It was said of a particularly successful hunter:{{sfn|Thomas|1959}}
 
:"It was said of him that he never returned from a hunt without having killed at least a wildebeest, if not something larger. Hence the people connected with him ate a great deal of meat and his popularity grew."{{sfn|Thomas|1959}}
 
Although this hunter was sharing meat, he was not doing so in the framework of reciprocity.{{sfn|Thomas|1959}} The general model of costly signalling is not reciprocal; rather, individuals who share acquire more mates and allies.{{sfn|Zahavi|1975}}{{sfn|Bliege Bird|Smith|Bird|2001}} Costly signalling applies to situations in Kalahari foraging groups where giving often goes to recipients who have little to offer in return. A young hunter is motivated to impress community members with daughters so that he can obtain his first wife. Older hunters may wish to attract women interested in an extramarital relationship, or to be a [[wikt:co-wife|co-wife]].{{sfn|Lee|1993}}{{sfn|Shostak|1981}} In these northern Kalahari groups, the killing of a large animal indicates a man who has mastered the art of hunting and can support a family. Many women seek a man who is a good hunter, has an agreeable character, is generous, and has advantageous social ties.{{sfn|Lee|1979}}{{sfn|Shostak|1981}}{{sfn|Marshall|1976}} Since hunting ability is a prerequisite for marriage, men who are good hunters enter the marriage market earliest. Costly signalling theory explains seemingly wasteful foraging displays.{{sfn|Hawkes|Bliege Bird|2002}}