Development of Behaviour Psychology 3106

Introduction So far we have looked at Evolution and Genetics Go together in the modern Synthetic Theory of Evolution Go together in the modern Synthetic Theory of Evolution Evolution acts on the phenotype Genetics (interacting with the environment) create the phenotype Development links genotype to phenotype

Introduction Development is the unfolding of the phenotype in a particular environment Not the Nature v Nurture ‘controversy’ again! That great Hebb quote Interaction principle is the key You cannot have genes without an environment, and vice versa, so get over it!

Important Ideas in Development Canalization or Developmental Homeostasis The capacity for structures to develop even if conditions are suboptimal The capacity for structures to develop even if conditions are suboptimal Ghysen (1978) Misdirected nerve cell in Drosophila Misdirected nerve cell in Drosophila Ganglion grew the wrong way Ganglion grew the wrong way Eventually projected to the right place! Eventually projected to the right place!

More Developmental Issues Well, that’s all very interesting Dr. Brainiac, but what about behaviour? Fine question…. Fine question…. Social Behaviour of Rhesus Monkeys (Harlow and Harlow)

The Evil Harlow

Those poor monkeys…… But, the nice thing was that when a normal monkey interacted with the messed up one, it could, in essence, give the poor guy therapy Even surrogate mothers worked! Even under such nasty conditions, normal development was possible (with a little environmental tweaking)

More Key Issues Sensitive Periods Animal’s nervous system needs certain input at a certain time or development will stop Human vision and me, for example Human vision and me, for example Development may not exactly stop, but it may turn out to be quite a bit different.

The lecture continues to develop Experience Expectant vs. Experience Dependent Information Storage Experience expectant Experience expectant Like information needed in a sensitive period Generallhy needed for all species members Experience Dependent Experience Dependent Individual level Makes individuals different

Imprinting Imprinting is another great example Pretty much the first thing a bird sees becomes its ‘mother’ Pretty much the first thing a bird sees becomes its ‘mother’ ‘Not Learning’ ‘Not Learning’ Clayton has found that Amount of NMDA receptors in IMHV increase by 57% after imprinting in chicks!

Song Learning In songbirds it In pretty much works like this: Males sing Males sing Females don’t Females don’t Marler thought that there was a ‘template’ in the bird’s brain. Needed to hear himself sing around d post hatch or he’d never sing Thought they could only acquire their own song

Listen to the pretty birdies….

Not quite a template eh Pete?

Hormonal effects are huge in development

Conclusions About Development Gene / Environment interaction Development is sort of the unfolding of the phenotype by the genotype (with environmental interaction Critical periods usually aren’t