I 
Table 17. — Rating scale 1 of presumed degree of social 
stress associated with time and place of birth in terms 
of the sum of the rating for place of birth and time of 
birth 
Time of birth 
Place of birth 
Place 
rating 
1947 
and 
March 
1948 
April 
and 
May 
1948 
June- 
October 
1948 
Time rating 
2 
4 
6 
South Alley 
Burrow 
1 
3 
5 
7 
Areas I and II 
2 
4 
6 
8 
North Alley 
Burrow 
3 
5 
7 
9 
Areas III and IV. . 
4 
6 
8 
10 
1 The lower the rating scale the less the stress experienced. 
For constellations A, C, D there are consistent 
trends of: (1) decreasing rates of maturation; (2) 
increasing proneness to enter traps: (3) more un- 
favorable social conditions surrounding early life; 
and (4) in general a greater frequency of wounds. 
The exception to the latter (i.e., 8.3 wounds for A 
constellation males between the ages of 278-400 
days) is attributable to the fact that these more 
dominant males were involved in fights with all 
the other groups of males and could not avoid 
being wounded some of the time, although they 
usually won. 
The E constellation of males presumably repre- 
sents those few individuals who, for a variety of 
reasons, remained under exceptional stress during 
their entire life span. Presumably the B constel- 
lation for females is just as real a group as it was for 
males, but an analysis similar to that for males, 
as shown in table 16, was not prepared since the 
discreteness of this group was not so apparent in 
figure 80 A. 
The trend of the evidence suggests the following 
formulations: 
1. The trap may be considered as a particular 
example of those goals which possess both positive 
and negative attributes affecting the degree of 
response elicited from the individual. 
2. The degree to which the negative or un- 
favorable aspects of the goal situation elicit avoid- 
ance of the goal is inversely related to the degree 
of emotional disturbance or stress experienced by 
the individual. Another way of phrasing this 
statement is that individuals who have unavoidably 
experienced many disturbing situations also seek 
out other punishing situations such as represented 
by capture in traps (see pp. 281 to 283). 
3. The social stress experienced by the individual 
during early life, which determines physical 
maturation, also modifies the degree of avoidance 
of the trap. 
4. Social stresses, which arise after the rate of 
maturation has been determined, and which are 
frequently unrelated to food attainment, may 
produce a marked decrease in the avoidance of 
traps. 
These formulations should be considered as 
hypotheses, which need further verification under 
more rigidly controlled conditions than were pos- 
sible during the history of this colony. 
5 . Food, Water and Elimination. 
A. The Sources of Food. The sources of food for 
the rats were (1) a nearly continuously and abun- 
dantly available supply of Purina Laboratory 
checkers, (2) an occasional small amount of 
garbage, and (3) a few natural food stuffs available 
in the environment. 
The Purina checkers were placed in a hopper 
directly in the center of the pen. This hopper 
would hold 100 pounds, and so with the exception 
of the last few months of the study it was easy to 
keep an adequate supply of this food always 
available. Even when this supply was temporarily 
exhausted at the times of high population density, 
it was usually possible to replenish the supply 
before the food caches formed by the rats were 
exhausted. On a few occasions during periods 
of trapping, food was purposely withheld for 
periods of 3 or 4 days in the hope that this might 
increase the hunger drive sufficiently to make the 
rats more liable to enter traps. Even during 
these periods, stored food appeared to be sufficient 
to sustain the rats in good health. 
The garbage placed in the pen rarely exceeded 
5 to 10 pounds at any one time. With few ex- 
ceptions when this food was available the rats 
ignored the Purina checkers and concentrated on 
eating and transporting the garbage until it was 
all gone. 
! 
99 
