PSYC 102
April 17, 2008
1. Darwin approach to explain human nature. Certain kinds of motivations to establish relationships; create friends etc. were “fitness enhancing” in the past which would promote survival and reproduction.
-Those motivated to be part of a community and being nice to others/making friends did better than those of our ancestors that were isolated.
-Researchers look at how these relationships benefit people. They found that most of the benefits are with kin/family. This is true for humans as well as other species.
-One of the first principles studied is that we tend to make the closest relationships with those that share our genetics.
- Evolution says we are competing with each other. Therefore, why would we help others? When we DO see cooperation, we must study it because it contradicts the Darwin approach of survival of the fittest.
 a. LIONS: A Female Lion will nurse any baby regardless of it being hers.
 b. BEES: Will do work for the queen to get her genes into the next generation.
 c. GROUND SQUIRREL: Will alarm when there is danger to warn the other squirrels at its own expense. It will get eaten in the process of warning the others.
*In all of these examples, genetics are the reason behind this behavior. These are all KIN related and are still passing their genes on. In these instances the animals are not really sacrificing anything. The Lions are usually sisters so all of the offspring are sharing genes. The bees’ workers are more related to the queen than to each other. When they help the queen, they are helping themselves. The squirrel will only give the alarm when his “family” is around. It will not alarm if there are stranger squirrels. Their altruism is actually selfish.
*When we study humans, we see the same sort of pattern. Our closest relationships tend to be family relationships. The extent to which we make sacrifices to others is with how closely related they are to us.
RECIPROCITY ALTURISM: Not all our relationships are with kin. You scratch my back I’ll scratch yours.
1. In animals, we usually see relationships based on the exchange of behaviors.
-There is a debate over this type of behaviors. There are some examples of this, but “Pure” reciprocity is harder to find.
A. VAMPIRE BAT: Likes blood and usually feeds on cows etc. Restricted to an unpredictable food source. What happens is some of them will go out and get attached to a cow and get more than they need, others may go out and get none. Researchers noticed that in the bat cave, there were sophisticated exchanges going on. Those with a lot of blood would regurgitate blood to those that did not. However, they were very restrictive to who they would exchange with. There was a mutual agreement between select bats. This was once believed to be PURE reciprocity, but there may be some kin sharing.
B. CHIMPANZEE: Those that had a grooming relationship would also share food. Often these were unrelated chimpanzees.
1. Usually start with a favor…then there is a deep seated feeling of reciprocity or owing them something for that favor. This relationship needs to be equal in some way. If one or the other tends to take advantage and reciprocity becomes uneven, the relationship tends to deteriorate.
INDIRECT RECIPROCITY: Being nice to the nice. Sometimes we do things that are nice and do not see the direct pay back, or it is not immediate. Is this true reciprocity?
*Reputation becomes a critical element in forming reciprocal relationships.
-Problem is that people can get cheated. A lot of evidence is that this cheating is a constant problem.
-It is a common thing for one to try and get a little more out of the relationship than they give.
-You can discriminate as to who you will share this relationship with. You will look for someone that “plays fair”.
1. Guppies: When a big fish threatens, two or more males will swim really close to the threat then swim very quickly in another direction. This is to save the group, but will also “show off” to the females. If one of the males backs off in the pursuit, the others will ostracize him.
2. Monkey: Sharing is expected. If he does not, and other monkeys see him do this, he will be ostracized. His reputation is at stake.
*One of the most powerful ways to get humans to behave. When others are watching we tend to do and act better than if no one else is looking.
*Gossip/word of mouth is the biggest way of providing information on who to form relationships with to a community. The majority of human interaction or language is in the form of gossip. Very important survival mechanism…who to trust and who not to trust.
*Some animals are sensitive to reputation and restrict reciprocal interactions to only those who have a history of playing fair. Whether we are nice or not depends on how it will affect our reputation. If we do not think it will affect our reputation, we are less likely to be nice.
*From an evolutionary point of view, there are reasons for us to be nice.
1. KIN BIAS:  Because they are related to us. We tolerate more with family.
2. RECIPROCAL ARRANGEMENT: Trying to get something from someone. The relationship might benefit us somehow.
3. REPUTATIONAL REWARDS: We want a good reputation within the community, even if there is no immediate reward. People are watching.

*Going back 1 million years, would it have been the case that mate attraction was discriminate or indiscriminate? Which would have been more fitness enhancing? Discriminate would be because certain traits were required for males and females. Some of these traits were related to reproduction.
*Operates at the level of “gut” attractions, not conscious evaluation. Why you are attracted to certain traits is not important, the behavior is. For example, we gross out with feces. We have the initial reaction that poop is disgusting. We don’t need to know the specifics to WHY we don’t like it; we just need to get away from it.
*Identify what types of attractions in members of opposite sex would have enhanced reproductive success in our ancestral past.
*Argues that problems of optimizing reproductive success would have been different for males and females. Thus, they would have lead to somewhat different reproductive strategies and attractions.
*There are some commonalities…reasonably good looking, honest etc. However, there are big differences after this.