BLA: The Role of Hormones in Human Behavior

Arnold Berthold (1849)

An experiment demonstrating the role of hormones in animals. 

Hormone tested: testosterone

Animal tested: roosters

Prior Knowledge: Testosterone is a hormone that is responsible for:  

1. Development of male sex organs in an human embryo 

2. Secondary development of sex characteristics in males during puberty 

3. Sex drive throughout a male's life 

Arnold Berthold was the curator of a local zoo in Gottingen. He performed one of the first endocrine / hormone experiments in history.

Aim: Berthold aimed to identify the effects of testosterone in behavior through the castration of roosters

Subjects: six castrated roosters

Method:

- Quasi-experiment: a quasi-experiment is a study that has most of the characteristics of a normal study, but is unable to control some potential factors (such as age or sex of the subjects)

Berthold surgically castrated six healthy roosters. Castration refers to when the testicles are removed, which consequentially stops the subject's production of the hormone testosterone. Then, Berthold divided the roosters into three groups of two roosters.

• Group 1: control group - the roosters were kept capons 
• Group 2: the roosters were transplanted the testicles of another rooster
• Group 3: the roosters were re-implanted with their own testicles

Hypothesis: unknown

Although the hypothesis is unknown, because Berthold was trying to identify the roles of testosterone in male behavior, it is likely that he predicted that testosterone was involved in the male-specific behavior of roosters.

Results:

It was observed that the castrated roosters were less aggressive, less masculine, and had lost their interest towards hens. Berthold observed the castrated roosters to have a lesser tendency to crow, fight and mate.

The roosters that had reacquired testicles (group 2 & group 3) behaved normally, as any other uncastrated rooster.

Autopsies of the roosters in groups 2 and 3 revealed that the re-implanted testicles did not re-establish nerve connections with the rest of the body.

Conclusion:

Testicles release a hormone (testosterone) that influences aggression and dominant male behaviors.

Connection to the topic: hormones in human behavior:

- Berthold was able to identify that a biochemical released by the testes (i.e. testicles) was largely the cause of male characteristics and male behavior. This is because the roosters that were kept castrated (group 1) did not show any male specific behaviors and also had lost physical characteristics of male roosters - see image below. 

Group 1 / Group 2 / Group 3

Evaluation:

- Berthold only tested animals: validity of this experiment is only relative to the tested species

- ^ However, human males also have testicles and their endocrine systems also secrete testosterone, so the results may be highly relevant to the human male population

- Animals were harmed in this experiment

- No humans were harmed in this experiment

- The experiment was performed in the mid 19th century: outdated

- This study encourages the study of the endocrine system and hormones in relation to human behavior.

SLA: All About Bobo Dolls (Albert Bandura 1961)

Social Learning Theory:
Albert Bandura of Stanford University first suggested the Social Learning Theory as a reaction against the passive conception of humans in behaviorism. (He believed that reducing behavior as "stimulus-response" was much too simplistic... he refers to himself as an adherent of social cognitivism.)

Social Learning Theory refers to the paradigm that suggests that society / culture passes on its norms to individuals within a group. Social Learning Theory assumes that humans learn behavior via observational learning - that people learn by watching models and imitating the model's behavior.

- The model can intentionally try to teach an agent how to behave. Examples: teachers, parents, priests 

- The model might not try to directly affect the agent. Examples: actors, media, television, passersby

The Social Learning Theory involves the following factors for an agent to be successful in imitating a model:

1. Attention: the model performing the act must catch the attention of the agent
2. Retention: the agent must be able to remember how the model was acting
3. Motor reproduction: the agent must be able to emulate what he observed from the model
4. Motivation: the agent must will to perform the observed act 

There are also factors that influence the agent's motivation to emulate the observed model:

1. Likeness: agents will feel more motivation to emulate a model if they feel alike it it
2. Consistency: agents are more likely to copy consistent behavior
3. Rewards / punishments: these will act as incentives / deterrents to copy a model (respectively)
4. Liking the model: the more an agent likes the model, the higher the chances are that the agent will emulate the model

- E X A M P L E -

Albert Bandura et al. 1961 - Bobo Doll Experiment

• Aim: To see whether children would imitate aggression that they observed modelled by at adult (Social Learning theory). Also, to see whether the gender-likeness of the model would influence the aggression in the children.
• Procedure: Children from the ages of 3-6 years old were used for this study. They were divided into groups depending on their level of aggression, classified by their teachers and their parents. One group of children observed a video of an adult repeatedly beating a Bobo doll.
  A second group of children simply saw a video of an adult assembling toys in a room.
  A third group saw no video (control group)
  *In groups 1 and 2, some children saw same-sex models while others saw different gendered models.
  After watching the video, the children were placed in a room with toys and told the toys were for different children. They were then taken to another room with a Bobo doll. 
• Results: Group 1 (that observed the aggressive model) was the most aggressive group. They expressed physical and verbal aggression. Female subjects were more prone to exercise verbal aggression while male subjects exercised physical aggression. They displayed signs of observational learning.
  When the boys saw the female models in the video hitting the Bobo doll, they exclaimed: "Hey! Girls shouldn't act like that!"... thus the agents / subjects were more prone to emulate same-sex models.
• Evaluation: