1. Models of Crowding Stokols equilibrium model (interaction approach) –Uses phenomenological (subjective) reports –Density/crowding distinction (physical vs. psychological measurement Freedman drive energization model –Hullian learning theory approach E = H x D where E = excitatory potential (probability of behaviour, H = habit strength (number of repetitions of a behaviour, D = drive (e.g., hunger, thirst, etc.)

2. Models of Crowding Milgram’s cognitive overload model –based upon G. Simmel’s model of urbanism Esser’s brain evolution model –Based upon Maclean’s brain evolution model

3. Milgram’s Cognitive Overload Model: Reactions to Overload Allocate less time to each input (brusque manner) Disregard low priority inputs Redrawn boundaries in social transactions—shift overload to others Receptor is blocked prior to entrance into system (unlisted telephone numbers) Filtering devices diminish intensity of inputs (answering machines) Creation of special institutions to absorb inputs/shield the individual

4. Personal Attributes Personality traits Momentary drive states Intelligence & other skills Environmental Qualities PhysicalSocial Amount &status configuration ofpower space Stressors Noise Heat Exposure time Experience of Stress Psychological Physiological Response to stress

5. Milgram’s Cognitive Overload Model: Reactions to Overload Allocate less time to each input (brusque manner) Disregard low priority inputs Redrawn boundaries in social transactions—shift overload to others Receptor is blocked prior to entrance into system (unlisted telephone numbers) Filtering devices diminish intensity of inputs (answering machines) Creation of special institutions to absorb inputs/shield the individual

6. Esser’s Crowding Model Crowding is overstimulation of the nervous system Maclean’s brain evolution model Oldest sectionbrain stem (crowding due to overload) limbic system (crowding when stimuli clash with expectations) neocortical (posthetic) brain (crowding due to excessive Newestnovelty in stimuli) section

7. Problems with Studying the Abnormal No phenomenological reports possible when studying psychotic patients Confound in joint manipulation of social and spatial density Different diagnostic groups may react differently to various environmental conditions (confounding variable) Limited adaptive mechanisms in institutionalized individuals Poor external validity (generalizability) Institutionalization in itself may produce peculiar behaviour

8. Role of Ethology Apply the methodology, not the results of ethology Heuristic value in stimulating research No phenomenological reports possible with animals Animal resources are much more limited than human resources

9. Generalizability of Laboratory Studies Limited time variable Weaker manipulations than real world crowding Projective/simulational research may be inappropriate Sex of subject is frequently confounded with sex of the group

10. Calhoun’s Research on Overcrowding in Rats Impossiblility of crowding in nature over a long time period as a result of population regulating forces: Territorial behaviour Relationship between weight and fertility in females

11. Behavioural Sink (Syndrome of Crowding Effects) Dominance hierarchy Pansexuality (multiple copulations, homosexual behaviour Faulty maternal care given to pups Passive, withdrawn behaviour of submissive male rats Adrenal gland enlargement Generalization to humans?