Crowding Into The Behavioral Sink

1
Crowding Into The Behavioral Sink

• Calhoun, J. B. (1962). Population Density and
  Social Pathology. Scientific American, 206,
  139-148.
• Presented by Edward Londono

2
Introduction

• Population density- the number of individuals in
  a given amount of space
• Crowding- the subjective population experience
  created by density

3
Theoretical Propositions

• Calhoun wanted to study the effects of high
  population density on social behavior.
• Does the stress of social interaction alter
  behavior?

4
Method

• Series of 3 studies
• 32-56 rats to start
• placed in a laboratory room 10ftx14ft wide
• glass ceiling for observation

5
Method (cont.)

• Room divided into 4 sections by electrified
  partitions
• sections 1 and 4 were end sections
• 3 led to 2 and 4
• 2 led to 1 and 3
• you could not cross from 1 to 4

6
Method (cont.)

• Pens contained feeders, waterers, and enclosures
  for nests
• plenty of food, water, materials for building
  nests

7
Method (cont.)

• Normally each section could contain 12 adults,
  which would allow for 48 rats
• Calhoun allowed rats to multiply to nearly
  double-80
• he observed the rats under these conditions for
  16 months

8
Results

• Males battle for dominance in all 4 pens
• in pens 1 and 4, when one male won dominance he
  was able to defend his pen by guarding the only
  entrance into the pen
• therefore, in pens 1 and 4 there was 1 male rat
  and a harem of 8-12 female rats
• behavior in these pens was normal

9
Results (cont.)

• This left about 60 or so rats crowded into the
  other 2 pens
• this is where Calhoun termed the phenomenon which
  he called the behavioral sink
• there were 4 extreme pathological behaviors he
  observed aggression, submissiveness, sexual
  deviants, and reproductive abnormalities

10
Aggression

• Rather than 1 on 1 fights, male rats were
  observed in brawls for dominant positions in the
  social hierarchy
• going berserk, attacking females and juveniles
• biting other rats on the tail

11
Submissiveness

• This group consisted of the most healthy looking
  rats in the pens because they avoided battles for
  dominance
• they were observed moving through the pens in a
  sort of hypnotic trance
• they were completely uninterested in sexual
  activity

12
Sexual Deviants (Probers)

• Hypersexual always on the prowl for receptive
  females
• not interested in fighting for status
• some even became cannibalistic
• refused to participate in natural rituals of
  mating

13
Sexual Deviants (Pansexuals)

• Attempted to mate with any rat indiscriminately
• males, females, and juveniles that were not in
  heat
• did not fight for dominance

14
Reproductive Abnormalities

• Females lost inclination to build adequate nests
• mothers lost maternal ability to transport young
  from one place to another
• they would forget some of the litter or sometimes
  abandon them
• females who were in heat were chased by large
  groups of males until they were unable to
  escape-these females experienced high rates of
  complications during pregnancy and delivery

15
Significant Findings

• One environment where the behavioral sink may
  occur is in extremely overcrowded prisons
• a study done by The National Institute of Justice
  found significantly higher rates of mortality,
  homicide, suicide, illness, and disciplinary
  problems

16
The Development of Mood-Inhibiting Effects of
Crowding During Adolescence

• Prerost, Frank J. Journal of Psychology, 1982,
  110, 187-202.

17
Theoretical Proposition

• Previous studies have found that human crowding
  causes unpleasant mood states which in turn
  produces stress
• Does crowding cause unpleasant mood states or
  does it inhibit pleasant mood states?

18
Method

• 3 groups of 24 males and 24 females
• groups ages were 13, 16, and 19
• each group was divided into groups of 6
• of the 4 groups of 6, 2 groups were placed in
  crowded settings and the others in a non-crowded
  environment

19
Method (cont.)

• Half of the crowded/non-crowded groups were
  presented with non humor reading
• the other half with 36 humorous jokes of a
  neutral, aggressive, and sexual nature (12 of
  each)

20
Method (cont.)

• Aferwards, mood was assessed with the
  Nowlis-Green Mood Adjective Checklist
• 5 mood states were presented aggression,
  euphoria, anxiety, social affection, and negative
  egotism

21
Results

• Findings suggest that crowding, rather than being
  an unpleasant stressful condition, suppresses
  positive mood and thereby enhances the
  possibility of negative-mood development
• males appeared to be influenced by the crowding
  more easily than females
• the effectiveness of the positive mood-producing
  stimuli (humorous jokes) was inhibited by
  crowding