Evolutionary Explanations for Group Displays

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  • Created by: Amy
  • Created on: 03-01-13 14:33

Group Displays

Warfare - From an evolutionary perspective the benefits of being part of a group during warfare will outweigh the costs to the individual

Benefits of forming a group in warfare:

  • Powerful
  • Greater protection
  • Increased chance of winning

Costs of warfare to the individual:

  • Less powerful 
  • Less protection 
  • Less chance of winning
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War Increases reproductive fitness

Success in battle can increase the warriors’  attractiveness to females thus improving his chances of reproducing offspring to continue his genetic line. The male is most likely to be victorious in a larger group than if he is alone. If this is the case, engaging in war gives the victorious group greater access to females improving their reproductive fitness. 

From an evolutionary perspective why might females find a victorious male more attractive than a male that has lost? 

They would have more status and be more dominant – therefore better able to provide and protect the family


During World War II Germans ***** women in concentration camps and in Bosnia (Yugoslavia) more than 20,000 Muslim girls and women were ***** by Serbians during religiously motivated violence

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How could this be explained from an evolutionary perspective? 

To make women pregnant and therefore raise children as Serbs (Serbian blood in the children would be considered more superior.) One group has status over the other (Serbs over Bosnians), access to land, women and resources

Why might victory in war lead to increased levels of aggression in the next generation? 

Less aggressive males will not survive war (could be that the losing group will have less surviving males) therefore aggressive gene will be passed on to the next generation creating an increasingly aggressive species

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Evaluation of reproductive fitness as an explanati

This is supported by research by Chagnon 1968, amongst the Yanomamo there is constant fighting for access to women or to improve status. In addition the tribe males who were successful warriors had more wives and children than those who were less successful in battle. Most young men who had killed were married; most young men who had never killed were not.

Why does this support the evolutionary explanation of war?

Supports the idea that group displays increase reproductive fitness

Evolutionary theory also explains why some individuals choose not to fight. Humans have evolved to recognise that group conflict should be avoided if the costs outweigh the benefits. This supports the evolutionary explanation because it shows that if males are not going to increase reproductive fitness by engaging in war (e.g. if losing is inevitable) then they would choose not to and live to pass on their genes.

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The evolutionary perspective can explain why women are less likely to engage in war. There is no reason why women should engage in war because their reproductive fitness is not affected by the number of available males. However, Ledyard 1995 found that when defending oneself against physical attack men and women are equally as likely to retaliate. And it does not explain why women still go to war.

What is a weakness of explaining war and atrocities associated with war such as **** using an evolutionary perspective?  

E.g. could make these acts seem acceptable. Ignores the cause/or reasons for war such as fighting because you ‘believe’ in something

-- An alternative explanation would be deindividuation theory this would explain that people engage in warfare because they feel anonymous, unidentifiable and less likely to be personally held responsible for their actions, therefore making it easier to engage in aggressive behaviour

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Takes a complicated behaviour and explains it simply.

Focus on Nature-

Ignores the environmental factors that can influence aggression such as social learning theory - a father might go to war and his son may do the same.

Gender bias-

Most research is carried out on men, mostly ignores women when women today still go to war


It suggests that our genes determine our behaviour, ignores free will

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Adaptive Explanations for Religious/Cultural Displ

In this section we are discussing self-inflicted violence. Self-inflicted violence is not uncommon during religious rituals. For example, the Shia Muslim practice of self-flagellation during Ashura, a major religious festival that commemorates the martyrdom of Hussein, a grandson of the Prophet Mohammed. Some men symbolically recreate the suffering of Hussein by flagellating themselves with chains and knives, or cutting their foreheads until they are covered in blood

Reasons for this from the evolutionary perspective are:

  • Accepted into group
  • Resources
  • Protection
  • Status
  • Increased reproductive fitness
  • Shows commitment to the group
  • Take in the strongest
  • Solidarity
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How is such behaviour adaptive?

  • Show your strength
  • Shows loyalty
  • Protection from group

How is such behaviour maladaptive?

  • They might die
  • Make yourself weaker and more vulnerable
  • Scarring could be recognised as part of a group and be open to attack from rival gangs
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Religious Displays = Cooperation

Irons (2001 – theory not evaluation): Living in a group has many benefits such as:

  • defence 
  • hunting
  • food sharing
  • warfare

Therefore, cooperation is essential.  Aggressive ceremonies and displays confirm the individual’s commitment to the group and shows that they are not a member simply for the benefits.

 Painful rituals promote commitment and cooperation within the group, so it is favoured by natural selection and is actually therefore adaptive.

Aggressive ceremonies and displays confirm the individuals commitment to the group and shows that they are not a ‘free rider.

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Costly displays deter ‘free riders’

The rituals are costly to the individual (painful / hardship to experience) so they therefore prevent free riders from joining the group.  

Zahavi (1975 theory) refers to these costly displays as handicaps (for example a peacock’s plumage attracts mates but also makes it difficult for the male to escape from predators).  

Handicaps can be indicators of attributes such as status, breeding potential and cooperation/commitment to the group as they are too costly to exhibit for no reason or by ‘low quality’ individuals. Thus, costly displays demonstrate cooperation and commitment and are adaptive.

Sosis (2006) supports this with the example of the Haredim who are an extremely Orthodox Branch of Judaism.  In the Summer in Israel they stand outside and worship God, pray and sing.  However they do this in thick coats, suits and hats so they become extremely hot while they do this.  This hardship again proves they are committed to their group (religion) and God.

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Evaluation of the adaptive explanations of religio

Religious displays (Ruffle and Sosis):

  • Religious males (Jews) are required to publicly pray three times a day – shows their commitment publicly (Ruffle and Sosis, 2005).
  • Whereas female’s commitment is displayed privately (baking and lighting Shabbat candles).
  • Therefore a male’s commitment to the religious group is displayed more visibly than a female’s commitment; lead to higher levels of group co-operation
  • This explains why religious males are more cooperative towards those in their kibbutz compared to religious females


By making group membership costly it serves as an adaptive advantage because it increases group solidarity and deters outsiders (‘free riders’) from taking advantage of the group.

One problem with this is the possibility of hostility between groups.

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Cultural Displays (Sosis et al):

  • Sosis et al (2005) suggests that the frequency of warfare is the strongest predictor of the costliness of the male’s ritual display.
  • so the more warfare the more costly the display
  • Intragroup solidarity = intergroup conflict
  • They also found that the type of display was also dependent on the nature of warfare.
  • External warfare (against other society) that involves uniting unrelated males  to form a large group leads to a more permanent, costly ritual (tattoo, scars etc).
  • Internal warfare = less costly group display
  • This prevents him from absconding to another group
  • All of this serves as an adaptive advantage because it increases cooperation and  commitment
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How are these explanations determinist?

Removes free will, self-inflicted violence is an innate response to the desire to belong to a group

How are these explanations reductionist?

Only reason people behave this way is to join a group, ignores other reasons such as rebelling, emotions etc therefore too simplistic

How are some of these studies/theories culture biased?

Specific cases from religions or cultures therefore may not apply to everyone

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