Imprinting

Imprinting is a rapid, irreversible form of learning that occurs during a narrowly defined critical period early in an organism's development, in which a young animal forms a strong attachment to the first moving object it encounters — typically its parent, but famously demonstrated by Konrad Lorenz to include any suitable substitute, including human researchers. Unlike associative learning, imprinting does not require reinforcement; a single exposure during the sensitive period is sufficient to establish a preference that lasts for life and shapes subsequent social and sexual behavior. The critical period itself is an adaptation: it ensures that imprinting occurs when the young animal is most vulnerable and most in need of following a protective figure, but it also imposes a rigidity that can be exploited. In natural settings, the first moving object is almost always the mother; the reliability of this cue makes the rigidity of the critical period adaptive rather than risky.

Imprinting is not a failure of learning. It is a learning mechanism optimized for speed over accuracy — and the environments it evolved in were predictable enough that speed was the right trade-off. But environments change, and the critical period does not.