Mennella and colleagues (2001) tested whether flavor preferences could be learned prenatally from exposure to amniotic fluid and in the first weeks of postnatal life through exposure to breast milk. Participants were assigned to one of 3 groups. One group of mothers drank carrot juice during their last 3 weeks of pregnancy and water during their first 2 months of breastfeeding. A second group of mothers drank water during their last weeks of pregnancy and carrot juice during their first 2 months of breastfeeding. A third group, drank water during the same periods of pregnancy and breastfeeding. Infants were tested with plain cereal and carrot-flavored cereal 4 weeks after months started adding cereal to infants’ diets. Infants in both carrot-juice groups showed a taste preference for carrot flavored cereal than infants in the control group. The carrot-exposed infants displayed fewer negative facial expressions to carrot-flavored cereal ate more carrot-flavored cereal compared with controls.

The participants in this study were:

a.
rat pups

b.
unborn fetuses

c.
infants

d.
zygotes