1. The Social Use of Space 129 



degree of difference type: 



Pga Puh Pg(.N-i) 



Equation (92) applies strictly only for that single individual which has 

 preserved all the dominant or ideal traits. For every other individual one 

 or more terms in Eq. (92) will be missing, depending upon replacement of 

 the dominant d-genes by recessive ones. Similarly Eq. (93) applies strictly 

 only to that individual in which all traits, other than those commonly 

 held (d) , have diverged from the ideal, that is in that individual in which 

 all non-(d) rf-genes are recessive. For all other individuals one or more 

 terms in Eq. (93) will be missing. 



Consider the case where all d-genes in a group had been identical up 

 until a particular point in time, at which a particular d-gene, g^^\ "mutated" 

 to g[^'^ in half the members. In this mutation gf^^' diverged sufficiently 

 from g[^^ to make quite distinct the derived from the original. Then the 

 probability of each in the group will be only 0.5 and thus the response- 

 evoking capacity of each will rise to a relative value of 2.0. For the average 

 individual S will have increased from 1.0 to 2.0. 



The total Nh members of a basic sized group will consist of Ni type 1 

 individuals possessing g[^^ and A^2 type 2 individuals possessing g[^\ Thus 

 ATj, = ATi + Ni. Any individual will be considered as being able to encounter 

 itself in the sense of being aware of its own characteristics. 



Considering this premise it follows that the probability pi of any type 1 

 individual being met by associates becomes: 



p, = N,/N, (94) 



Similarly, the probability, pa, of type 2 individuals being met by as- 

 sociates becomes: 



p, = N2/N, (95) 



From Eq. (87) it follows that response-evoking capacity, *Si, of any 

 type one individual, and S2 of any type two individual will be respectively: 



S, = Nb/Ni (96) 



S, = Nb/N2 (97) 



Therefore, the mean response-evoking capacity, S, of the Nb individuals 

 becomes: 



Ni-^ N, 



