According to havighurst, when children aged 0-5 fail to navigate through developmental tasks, they may experience

They may experience "unhappiness, disapproval of society, and difficulty with later tasks". Before it was believed that the infant was not aware of what was happening around him, however, various investigations have shown that the first years of life are essential for the child's cognitive and social development. The child who feels that he can not perform the tasks of his environment and does not obtain the necessary support develops with an insecure attachment, fearful of interpersonal relationships or considering himself inferior to his peers.

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