Figure 1: Experimental designs to explore a sensitive period of peer-social learning
a. Five developmental conditions of peer-social environment
Besides the bipolar sets, isolated (Iso) and grouped (Grp), three kinds of five-day grouped with ten-day isolated conditions (GII, IGI, and IIG) were evaluated
b. Parameters of local preference to interpret a subject’s social distance to the reference peers (see also e)
c. The scene of a behavioral test on P15
d. Four types of chicks’ typical calls
e. Fifteen parameters to be extracted from video-recorded behavioral data