Lecture 13: Play Flashcards
A definition of play (from Bekoff and Byers 1981):
“Play is all motor activity performed postnatally that appears to be purposeless,
in which motor patterns from other contexts may often be used in modified forms and
altered temporal sequencing.
If the activity is directed toward another living being it is called SOCIAL play.”
Problems with Bekoff & Byers definition of play:
Play can’t be PURPOSELESS as its costly. There must be a benefit which outweighs these risks! (time delay tho)
a. observer may fail to decipher the immediate
benefit (or function) of play
b. the true benefit (function) may not occur until much later
c. the benefits (i.e. functions) may be multiple and confounding
costs of play:
energetic, reduced vigilance, increased predation, risk of injury
Look at the mechanism of play by constructing
ETHOGRAM: complete inventory of animals behavioural repertoire but that doesn’t tell us anything about the function of play or why it evolved.
Taxonomic occurrence of play:
1) Mammals
- especially carnivores, ungulates and rodents: it also varies between species - young rats play a lot, young mice don’t
2) birds
-especially members of the Corvidae
Also in other animal groups although apparently less frequent and not well-studied
Can we study play scientifically?
play is related to happiness? We can’t measure fun or happiness
play studied in 1970s& 80’s
focus on structure and mechanism
Three types of play:
-Object play
-Locomotor play
-Social Play
..NOT mutually exlusive
Object play:
- play or exploration?
- best seen in juveniles
- ‘practice’ for behaviours such as hunting for food? or do infants just have more free time
- object play most seen in predatory and scavenging species, youngsters most interested in playing novel food objects (e.g.RAVENS)
object play by predators examples:
- cats playing with rodent prey
- Gulls catching tired migrants and dropping them
- kingfisher catching sticks
Locomotor play two hypothesis for function:
- may provide general exercise allowing development of motor skills for later life (– Cerebellar synaptogenesis formation in mice but Correlation not causation)
- may provide better understanding of the ‘lay of the land’, helping to develop better spacial awareness.
Social play Hypotheses for function: + example
a. Enhances physical skills
b. Facilitates long term
relationships
c. Enhances cognitive skills
–rough & tumble in tigers play fighting
smiling gorillas:
2 expressions in play:
- Mouth open + teeth covered
- Mouth open + teeth visible
- —> different signals
Other social play signs: (dogs)
- vocalisation
- Tail (posture& wagging)
- Body postures (Bow, Roll on back, Crouch and stare, Outstretched paw)
- Ambulatory (Gamboling, stalking, shaking)
- Head (Shaking, ear, eye movements,open mouth)
Intensity and direction of actions focused on social partne
Why play fair?
- The gains from ‘cheating’ are low
- But the costs (exclusion from the group) can be significant and long-lasting
- – Feels like pain?
