Previous research using the name-based categorization task has shown that 20-month-old infants can simultaneously learn 2 words that only differ by 1 consonantal feature but fail to do so when the words only differ by 1 vocalic feature. This asymmetry was taken as evidence for the proposal that consonants are more important than vowels at the…

In laboratory studies of social referencing, infants as young as 12 months have been reported to prefer looking at the experimenter over the caregiver for clarifying information. From an expertise perspective, such behavior could be interpreted as if the infant seeks information from others and can discriminate between persons who have or do not…

Four experiments investigated infants' preferences for age-appropriate and age-inappropriate infant-directed speech (IDS) over adult-directed speech (ADS). Two initial experiments showed that 6-, 10-, and 14-month-olds preferred IDS directed toward younger infants, and 4-, 8-, 10-, and 14-month-olds, but not 6-month-olds, preferred IDS directed…

People often express excitement to each other when encountering an object that they have shared together previously in some special way. This study investigated whether 14-month-old infants know precisely what they have and have not shared in a special way (and with whom). In the experimental condition an adult and infant shared an object (the…

Human infants readily interpret the actions of others in terms of goals, but the origins of this important cognitive skill are keenly debated. We tested whether infants recognize others' actions as goal-directed on the basis of their experience with carrying out and observing goal-directed actions, or whether their perception of a goal-directed…

Adults, preschool children, and nonhuman primates detect and categorize food objects according to substance information, conveyed primarily by color and texture. In contrast, they perceive and categorize artifacts primarily by shape and rigidity. The present experiments investigated the origins of this distinction. Using a looking time procedure,…

Relations between infant-mother attachment security at 15 months and infants' (N = 206) joint attention behaviors (a) with an experimenter at 8 and 15 months, and (b) with their mothers at 15 months were investigated. No concurrent or longitudinal relations were observed between attachment security and infants' tendency to respond to an…

When are the precursors of ordinal numerical knowledge first evident in infancy? Brannon (2002) argued that by 11 months of age, infants possess the ability to appreciate the greater than and less than relations between numerical values but that this ability experiences a sudden onset between 9 and 11 months of age. Here we present 5 experiments…

With a series of four experiments we show that self-produced actions influence infants' perception of actions performed by others. After having played with an object, 7-11-month-olds simultaneously watched two videos presenting adults who act on either the same object or a different one. The 9- and 11-month-old preferred to watch the same-object…

Objective: To examine prospectively the emergence of behavioral signs of autism in the first years of life in infants at low and high risk for autism. Method: A prospective longitudinal design was used to compare 25 infants later diagnosed with an autism spectrum disorder (ASD) with 25 gender-matched low-risk children later determined to have…

Young babies are easily overwhelmed by the pain of hunger or gas. However, when an infant's day is filled with caregiving experiences characterized by quick responses to his cries and accurate interpretations of the meaning of his communication, the baby learns that he can count on being fed and comforted. He begins to develop trust in his teacher…

A randomized controlled trial involving 128 infants born prematurely compared basic developmental care (nests and incubator covers) and the Newborn Individualized Developmental Care and Assessment Program (NIDCAP) intervention (behavior observations and guidance by a trained developmental specialist) in relation to effects on parental stress and…

Recently, several studies have claimed that soon after their first birthday infants understand others' false beliefs. However, some have questioned these findings based on criticisms of the looking-time paradigms used. Here we report a new paradigm to test false belief understanding in infants using a more active behavioral response: helping.…

The efficacy of the paraprofessional-delivered Family Spirit home-visiting intervention for young American Indian mothers on maternal knowledge and infant behavior outcomes is supported. Participating mothers showed greater knowledge gains compared to non-participating mothers.

Previous studies have shown that 7.5-month-olds can track and encode words in fluent speech, but they fail to equate instances of a word that contrast in talker gender, vocal affect, and fundamental frequency. By 10.5 months, they succeed at generalizing across such variability, marking a clear transition period during which infants' word…