Hasett et al (monkey toys experiment)

biology

socialisation

the process of learning to behave in socially acceptable ways, this may differ somewhat for the 2 genders

gender stereotype

a bias exhibited in society that may be held by people and represented

e.g. books, toys that assign particular traits, behaviours,…

sex differences

differences in the mental functions & behaviors of the sexes and due to complex biological, developmental and cultural factors

stereotypical

fixed beliefs about a particular group of people, and behaviors individuals show in a particular situation are affected by expectations

e.g men are strong, women are caring

CAH (congenital adrenal hyperplasia)

people exposed to higher than usual levels of prenatal androgens (male sex hormones)

play

behavior typical of childhood thats done for fun rather than any useful purpose. objects designed to play are “toys”

Aims

1. test if sex differences in children’s toys result from biological factors

2. test if monkeys have similar toy preferences to human infants, despite no sicialisation experiment with human toys

type of experiment

field experiment - research centre where monkeys are raised for 25 years thus it is their natural environment

experimental design, IV groups, trials

independent measures design

2 groups of monkeys - males and females

7 trials, each w different pair of toys, 25 mins

variables

IV - naturally occuring

DV - whether monkeys interacted more with plush or wheeled toys

plush toys

winnie the pooh, rageddy ann, scooby doo, teddy, koala, turtle (16-64cm)

wheeled toys

truck, wagon, supermarket cart (14-73cm)

sample

135 monkeys, 34 monkeys interacted w the toys more and were included in the analysis (23 females, 11 males)

procedure

7 25-min observations in the outdoor area of research centre

1. toys are placed 10m apart outdoors (wheel right, plush left) → more accurate

2. toys varied in size and color are selected based on what you could do w them

3. a video camera is focused on each toy

4. use a behavioral checklist to catagorize interactions (used handobs app, record data using palm pilots

5. record rank, age, sex after each interaction

behavior checklist

extended touch ———-place a hand or foot on toy

hold ————————-stationary support w 1/more limbs

sit on ———————--seated on the toy

carry in hand ————-moving w toy in hand & off the ground

carry in arm ————--moving w toy in arm & off the ground

carry in mouth ———-- moving w toy in mouth & off the ground

drag ————————moving the toy along the ground behind the animal

manipulate part ———moving, twisting, turning a part

turn entire toy ————shifting 3d orientation of toy

touch ———————-brief contact using hands or fingers

sniff ———————--coming very close to the toy w nose

mouth ———————brief oral contact - no biting or pulling

destroy ——————-bite/ tear toy

jump away —————approach then jump away from toy

throw ———————-project into air with hands

duration of interactions

• females (1.27 min) didnt play with wheeled toys as long as the males did (4.76 min)

• no significant between the duration of playing w plush toys

results

• monkeys < 5 behavior → discounted

• most monkeys didnt interact

• male preferred wheeled > plush → not affected by age or rank

• females show no consistent preference, plush > wheel but not significant

results (social rank & toy preference)

• significant positive correlation between social rank & frequency of interactions

• higher ranking monkeys interacted more

• females - higher rank → more time w plush toys

strengths

ethnics:

• animals dont face tangible harm & they still have their needs

reliability:

• operationalized behavioral checklist → clear outline

validity:

• 7 trials, 25 mins, different toys → remove the possibility that they might be attracted to a toy bcs of their personal preference

• use of cameras → wouldnt change behavior w humans around

• quantitative data → avoid subjective intepretation

weakness

reliability:

• standardized procedure was abandoned when a monkey ripped a plush toy

• trial was ended 7 mins early as researchers were unable to observe monkey’s preference → reduce reliability

validity:

• potential observer bias - researchers are familiar w the monkeys → unintentionally coded monkey’s behavior differently

generalization:

• lack of adults males → only be generalized to lower ranking, non adult males

• conducted w monkeys in captivity → decrease ecological validity → unclear if wild monkeys would behave this way