Hasset et al (2008)

Why do Children Play?

For socialization and stimulation

• What are typical male vs female toys?

• Children play to stimulate their minds, entertain themslevs, explore the world, and build soci relationships.

Background: General

• Boys tend to interact with masculine-type toys esp. stereotyoical masculine, and girls tend to interact wit feminie-tyoe toys but play with both.

View 1

• Socialization: parents or peers encouraging play with specific toys are thought to be the primary force shaping sex differences in toy preferences.

View 2

• Toy preferences reflect biologically determined preferences for specific activities facilitated by specific toys.

View 3

• Hormones are the source of differences.

• Girls with genetic condition which causes increased prenatal male sex hormones show toy preferences more in line with boys than girls.

• When encouraged to play with female toys, they refuse and prefer male toys.

Aim

• To investigate whether sex differences in toys preferences of rhesus monkeys resemble those in children in order to test whether sex differences in toy choice is biologically determined by sex.

Method

• Field experiment with observation of monkeys in their natural enclouser

• Researchers controlled the area so they could place toys & videotaped the monkeys to review later.

• Another control would be standerdized procedure with each monkey

• IV: gender (naturally occuring)

• DV: measured if they interact more with plush toys or wheeled toys

• Once they placed with toys their social work and age were recorded

Sample opportunity + participants

• 21 males & 61 females rhesus monkeys living in a multi-male, multi female social group of 135 animals at the Yerkes Primate Research Station, USA for 25 years.

• 14 adults not studied b/c they had recieved hormone treatments.

• 39 infants excluded b/c they could not be reliably indentified.

• Housed in 25×25 meter outdoor compounds wit attached temperature-controlled indoor quaters.

• Water was continously available, and the animals were fed monkey chow twice daily, supplemented once per day with fruits and vegetables.

Materials

• The toys used by Hasset were not categorized by traditional gender assignments, but by specific object propeties that made the categories comparible.

• Wheeled - A wagon, a truck, a car, a construction vehicle, a shopping cart, and a dumptruck.

• Plushed - Winnie-the-pooh, Raggedy Ann, a Koala bear hand puppet, an armadillo, a teddy bear, Scooby doo, and a turtle.

Procedure

• For each social group, seven trials each lasting 25 min. were observed with 2 video cameras.

• Each trial began with all the monkeys in the group indoors while one wheeled and one plush toy were placed 10 m apart in the outdoor enclosure. Plush & wheeled toys were counterbalanced b/w left & right location for each trial.

• Monkeys were then released into the outdoor area and each toy and any animal interacting with it was videotaped using separate cameras for each toy.

• After each trial, toys were removed from the outdoor area.

• The identity of every animal interacting with the toys and specific behaviors directed towards the toys were coded from the videotapes by two observers working together to achieve consensus on both identity and behaviors.

• In one case, a plush toy was torn into multiple pieces, ending the trial 7 min early.

Results: Data Analysis

• Observers calculated average frequencies & durations for each behavior

• Then they calculated the total number and total duration of interaction with each toy type by adding up the averages for each individual behavior.

• Subjects with fewer than 5 total behaviors (3 males and 14 females) were excluded from analyses. Producing a final total of 23 females and 11 males.

Results

• Males significantly preferred wheeled toys compared to the plush toys.

• Females showed no significant preference for plush toys over the wheeled toys.

• Males showed significantly lower frequency of play with the plush toys compared to the females.

• There was a significant positive correlation between rank and with frequency of interaction for both types of toys. Higher-ranking monkeys interacted more with the toys.

• For females, the higher the rank the more time spent interacting with plush toys but not wheeled toys.

Conclusion

• Like boys, male monkeys have a strong preference for masculine-type toys (wheeled)

• Like girls, female monkeys are more variable in toy preference

• This supports a biological explanation as monkeys don’t get ‘socialized’ to like certain toys

• In humans, there is more negative responses for boys playing with girls’ toys than for girls playing with boys’ toys = social pressure

Strenghts

• Strengths

  • Ecological validity (field experiment)

  • Standardized procedure - increased reliability & replicability

  • Researchers controlled for confounding variables such as socialization by using monkeys

  • Data Collection - use of checklist 

    • 2 observers = inter-observer reliability

    • Use of video cameras to analyze monkey’s behavior

Weaknesses

• Toy choice for monkeys was just wheeled vs plush for human children it was much more varied

• The most significant comparison was for frequency for monkeys and duration for children, rather than using both

• Used captive monkeys so not a true field experiment (it was conducted in their natural enclosure)

• Generalizability - more females than males at the end for data analysis

GRAVE Evaluation

Generalizability - This study has poor generalisability, as the sampling technique was opportunity. This means that it may not be generalisable to other captive or wild rhesus monkeys. There is a similar problem when studying humans in this way, we call this ethnocentrism.

Reliability - This study’s reliability is very good as they used a standardised procedure including where the toys were placed and the toy chosen. This means that another researcher could easily replicate this study and test for reliability.

Application - The results could be very useful for toy manufacturers, specifically to include wheels on toys for boys. Also, this could help in the rehabilitation of rhesus monkeys rescued from the wild, to help with social bonding through play.

Validity - Validity is good. There were two observers who reviewed the video evidence. Also, the use of a structured observation via the use of a behavioural checklist allows objective quantitative data to be collected. However, this study lacks mundane realism.

Ethics - Very good. The rhesus monkeys were already living together for more than 25 years at the Yerkes National Primate Research Center Field Station. They had access to a varied diet and lived in social group, as you would observe in the wild. Also, no children were used in the study. The data was reused from a previous study.

Issues and Debates

Nature vs Nurture:

Nature argument is strong, esp. when you compare the results human results. However, the results from the human trials only included 15 females and 18 males which is a small sample, also the toys used were different.

The nurture argument can be supported, as the results show that the females don’t really have a preference for stereotypically gendered toys. Suggesting that socialisation of boys is what is driving the differences observed. This may link to social learning or rewards/punishments for boys.