Final answer:
Newborn infants prefer to look at human faces and have preferences for voices, especially their mothers, as part of their developing sensory abilities. They also show a preference for sweet tastes and can recognize the smell of their mother. Reflexes such as sucking and grasping are critical for their survival.
Step-by-step explanation:
Researcher Robert Fantz discovered that newborn infants have a clear preference for looking at human faces above all else. This preference for faces is part of a newborn's sensory abilities, which are significant yet not fully developed. The vision of newborns is the least developed sense but still allows them to prefer faces and facilitate interaction with caregivers. Additionally, newborns already have preferences when it comes to sounds, preferring the sound of human voices over non-speech sounds and showing a fondness for their mother's voice. As for the sense of smell, babies can distinguish the smell of their own mother from that of others from a very young age.
Regarding taste, newborns respond to and generally prefer sweet tastes. This preference is thought to be influenced by the mother's diet during pregnancy, as the amniotic fluid takes on the flavors of the food consumed by the mother which the baby tastes before birth.
Newborn infants also exhibit a number of instinctive behaviors or reflexes such as sucking and grasping, which are important for survival. For example, the root reflex assists the newborn in finding the nipple by turning its head in the direction of a touched cheek, ready to suckle. These reflexes are fundamental to the early stages of infant development and help ensure that the infant's needs for nourishment and protection are met.