Figure 1: Experimental designs and quantified parameters from behavioral test. a. The experimental procedure for comparison between group-reared chicks (Grp) and socially isolated chicks (Iso) (see details in Materials and Methods). The age, embryonic day 21 (E21) is usually the day of postnatal day 1 (P1) b. The list of behavioral factors extracted from the video data during behavior test. The definition of each behavior factor and the test condition were described in detail under Materials and Methods c. Social meeting test of a subject (left) and three reference peers which were unfamiliar to the test subject (right). The test comprised of four contexts (2min each) and only third context (visually and acoustically interactive) was illustrated here and the behavior data during the context was used for further analysis d. The definition scheme of local preference (LP-C, E, G and O) was illustrated, which related with personal distance [33,34] and emotional/ cognitive response to other environmental condition e. Each spectrogram example of two kinds of vocal calls: a distress call and an intermediate call. The detailed definition was described in Materials and Methods