Some children do not fit any of these patterns, but rather show blends of different temperament characteristics. Early in life, children show marked individual differences in temperament, indicating the important roles that biological factors play in determining temperamental styles. However, the changes shown by children suggest that temperament can be modified by experience. Findings of twin studies reveal that identicals are more similar than fraternals across a wide range of temperamental traits and personality measures. About half of individual differences among us can be traced to differences in our genetic make-up.
Boys tend to be more daring than girls.
Some differences in temperament are encouraged by cultural beliefs and practices. For example, Japanese mothers do more comforting and American mothers do more stimulating of their babies. Parents often encourage infant sons to be physically active and daughters to seek help and physical closeness. Research indicates that when one child in a family is viewed as easy, another is likely to be perceived as difficult, even though the second child might not be difficult when compared to children in general. Difficult children are less likely to receive sensitive care.