Hassett et al (monkey toy preference )

State the AIM of the Hassett et al study. [2] (To investigate [ ] in order to test [ ].)

To investigate whether toy preferences in monkeys resemble those in children in order to test whether sex differences in toy choice are biologically determined by sex.

State the method and design of the Hasset et al study. [2]

A field experiment (conducted in the monkeys' typical environment) using independent measures - the IV was the sex of the monkey.

Describe the main means of data collection in the Hassett et al study. [4]

-Data was gathered through a structured observation with a list of specific behavior categories including hold, sit on, sniff, mouth, destroy.

-2 observers coded behavior working together to ensure correct identification of animals

-Behavior was recorded on one video trained on each toy

Describe the correlation that was conducted as part of the Hassett et al study. [1]

Rs looked to see whether there was a correlation between rank within the social hierarchy and the frequency or duration of activities with each toy type.

State the two types of data that observers noted in the Hassett et al study. [2]

-frequency of each activity
-duration of each activity (how long the monkey did it)

Describe two differences between the Hassett study on rhesus monkeys and the experiment on children the researchers used to compare. [2]

-Children study (conducted by other researchers) measured duration of interaction with toys, while the Hassett researchers used frequency.

-Children were tested individually, while monkeys were tested in groups.

Describe how researchers transformed the raw data for each monkey. [1]

Rs calculated an average overall frequency and duration for each animal, excluding any with fewer than 5 total recorded behaviors.

There were 135 rhesus monkeys living at the Yerkes Primate Research Station.
a. Describe 2 reasons why some were excluded from the experiment.
b. Identify how many males and females took part in the experiment.

a. Some had received hormone treatments, and young infants were excluded because they could not be reliably identified.
b. 61 females, 21 males

State the two categories of toys used in the Hassett study. Give 2 examples of each type. [4]

Plush: Raggedy-Ann, Winnie-the-Pooh, Scooby-Doo, teddy bear, turtle, koala hand puppet, armadillo

Wheeled: car, truck, wagon, construction vehicle, shopping cart, dump truck

Describe the procedures of the Hassett et al study. [3]

-7 trials for each social group
-25 minutes each
-All monkeys began indoors
-1 plush toy and 1 wheeled toy were placed 10 meters apart outdoors
-Location of wheeled and plush toys were counterbalanced between left and right locations

Describe how the monkeys in the Hassett et al study were maintained at the Yerkes Primate Research Center. [3]

-Housed in a 25 x 25 metre outdoor area
-with access to a temperature-controlled indoor environment
-lived in matrilineal social groups
-Consistent access to water
-Given standard monkey feed twice per day
-Given additional fruits and vegetables once per day

Outline a within-sex frequency result for males and females. [2]

Males preferred wheeled toys (9.77) to plush toys (2.06).

Females did not show a statistically significant preference for plush toys (7.97) over wheeled toys (6.96).

Outline a between-sex frequency result for each toy type. [2]

Females interacted with plush toys more frequently than males did.
There was no significant sex difference in number of interactions for wheeled toys.

Outline a within-sex result related to duration. [1]

Males played with wheeled toys for longer than plush toys.

There was no significant difference in duration between wheeled and plush toys for females.

Summarize what Hassett et al found about monkey toy preferences. [2]

73% of male monkeys showed a preference for wheeled toys, while only 30% of females showed a preference for plush toys, suggesting males show much stronger sex differences in toy preferences.

Identify two variables, other than sex, which Hassett et al investigated as possible confounding variables in their study on sex differences in toy preferences. [2]

-social rank
-age

Outline two conclusions from the Hassett et al study. [2]

1. Like boys, male monkeys show a stronger preference for masculine-type toys. Female monkeys are more variable in their toy preferences.

2. The monkey data suggests a biological explanation for toy preferences, even in the absence of socialization.

Describe two strengths of the Hassett et al study.

1. Systematic investigation and elimination of confounding variables (rank and age) to increase internal validity
2. Highly standardised observation process with clear operational definitions to increase reliability

Describe two weaknesses of the Hassett et al study.

1. The monkeys were tested in groups while the children were tested individually, which limits the comparability of the two studies.
2. The main comparison was between frequency for monkeys and duration for children, limiting the comparability of the data.
3. Another study, conducted on vervets, found a completely opposite conclusion (females with stronger sex preferences for toys), undermining the confidence in the biological explanation for sex differences in humans.

Identify what Hassett et al believed was the reason for sex differences in toy play. [1]

Children prefer different activities as a result of different pre-natal hormonal environments.

Outline one assumption of the biological approach and explain how the Hassett et al study demonstrates it. [2]

Assumptions:

1. Behaviour, cognitions and emotions can be explained in terms of the working of the brain and the effect of hormones, genetics and evolution.

2. Similarities and differences between people can be understood in terms of biological factors and their interaction with other factors.

Application to Hassett:

Hassett proposed that sex differences in toy play were a result of differences in the pre-natal hormonal environments of males and females. In monkeys, these are strictly biological, while in humans, the hormonal differences interact with human socialization processes.