CHAPTER III 
Tue INSTINCTIVE REACTIONS OF YouNG Cuicxs! 
THE data to be presented in this article were obtained in 
the course of a series of experiments conducted in connec- 
tion with the psychological laboratory of Harvard Univer- 
sity during the year 1896-1897. About sixty chicks were 
used as subjects. In general their experiences were entirely 
under my control from birth. Where this was not true, the 
conditions of their life previous to the experiments were 
known, and were such as would have had no influence in 
determining the quality of their reactions in the particular 
experiments to which they were subjected. It is not worth 
while to recount the means taken so to regulate the chick’s 
environment that his experience along certain lines should 
be in its entirety known to the observer and that conse- 
quently his inherited abilities could be surely differentiated. 
The nature of the experiments will, in most cases, be such 
that little suspicion of the influence of education. by_ex- 
perience will be possible. In the other cases I will mention 
the particular means then taken to prevent such influence. 
chicks from 18 to 30 hours old, just old enough igh to move 
about readily and to be hungry. On backgrounds of white 
and black cardboard were pasted pieces of colored. paper 
about 2 mm. square. On each background there were six 
1This chapter appeared originally in the Psychological Review, Vol. VI, 
No. 3. 
: 156 
