Neonates of different species are born with a set of predispositions that influence their early orienting responses toward the first stimuli encountered in their life. Human neonates and domestic chicks exhibit several similarities in the predisposition for attending to objects that move with speed changes, face-like stimuli and biological motion. Although early predispositions are connected to physiological development, little is known on the temporal course of early predispositions (whether they are stable or change in time) and on the associated genetic variability. To address these issues, we tested the preference for objects that change in speed vs. linear motion in three chicken breeds (Padovana, Polverara and Robusta maculata) within one day after hatching and three days after hatching. We found that the predisposition to preferentially attend to changes in speed is shared by different breeds on the first day of life and that it disappears by day three. These results indicate the existence of a short and transient time window of early predispositions that does not depend on visual experience.

Neonates of different species are born with a set of predispositions that influence their early orienting responses toward the first stimuli encountered in their life. Human neonates and domestic chicks exhibit several similarities in the predisposition for attending to objects that move with speed changes, face-like stimuli and biological motion. Although early predispositions are connected to physiological development, little is known on the temporal course of early predispositions (whether they are stable or change in time) and on their genetic basis. To address these issues, we tested the preference for objects that change in speed vs. linear motion in three chicken breeds (Padovana, Polverara and Robusta maculata) within one day after hatching and three days after hatching. We found that the predisposition to preferentially attend to changes in speed is fixed at the species level on the first day of life and that it disappears by day three. These results indicate the existence of a short and transient time window of early predispositions that does not depend on visual experience.

The ability to recognise familiar individuals and the motivation to stay in contact with conspecifics are important to establish social relationships from the beginning of life. To understand the genetic basis of early social behaviour, we studied the different responses to familiar/unfamiliar individuals and social reinstatement in 4-day-old domestic chicks (Gallus gallus) in three genetically isolated breeds: Padovana, Polverara and Robusta. All breeds showed a similar ability to discriminate between familiar and unfamiliar individuals, staying closer to familiar individuals. Social reinstatement motivation measured as the average distance between subjects, latency to the first step and exploration of the arena (a proxy for the lack of fear), differed between breeds. More socially motivated chicks that stayed in closer proximity, were also less fearful and explored the environment more extensively. These results suggest that modulation of social behaviour shows larger genetic variability than the ability to recognise social partners, which appears to be an adaptive ability widespread at the species level even for very young animals.

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