They would rather listen to a tape recording of a woman's voice than a man's voice. The higher female pitch may be more interesting. Studies have shown that babies 4-6 months old can discriminate between facial expressions. They look longer at happy faces than at frowning ones. Even babies this young can react to an adult's mood.
Babies are also sensitive to a parent's mood through touch.
They can sense the tension, nervousness or hostility in a person's body and movements. If you are angry or upset, give yourself time to calm down before picking up and handling your baby. Irreparable physical and psychological harm can be done to a baby by a parent who is emotionally out of control. Realize that some babies are difficult babies. They may have irregular and unpredictable feeding and sleeping patterns.