Language development in the context of Jean Berko Gleason

Joint attention or shared attention is the shared focus of two individuals on an object. It is achieved when one individual alerts another to an object by means of eye-gazing, pointing or other verbal or non-verbal indications. An individual gazes at another individual, points to an object and then returns their gaze to the individual. Scaife and Bruner were the first researchers to present a cross-sectional description of children's ability to follow eye gaze in 1975. They found that most eight- to ten-month-old children followed a line of regard, and that all 11- to 14-month-old children did so. This early research showed it was possible for an adult to bring certain objects in the environment to an infant's attention using eye gaze.

Subsequent research demonstrates that two important skills in joint attention are following eye gaze and identifying intention. The ability to share gaze with another individual is an important skill in establishing reference. The ability to identify intention is important in a child's ability to learn language and direct the attention of others. Joint attention is important for many aspects of language development including comprehension, production and word learning. Episodes of joint attention provide children with information about their environment, allowing individuals to establish reference from spoken language and learn words. Socio-emotional development and the ability to take part in normal relationships are also influenced by joint attention abilities. The ability to establish joint attention may be negatively affected by deafness, blindness, and developmental disorders such as autism.

Pointing is a gesture specifying a direction from a person's body, usually indicating a location, person, event, thing or idea. It typically is formed by extending the arm, hand, and index finger, although it may be functionally similar to other hand gestures. Types of pointing may be subdivided according to the intention of the person, as well as by the linguistic function it serves.

Pointing typically develops within the first two years of life in humans, and plays an important role in language development and reading in children. It is central to the use of sign language, with a large number of signs being some variation on pointing. The nature of pointing may differ for children who have autism or who are deaf, and may also vary by gender. It is typically not observed in children who are blind from birth.

Simultaneous bilingualism is a form of bilingualism that takes place when a child becomes bilingual by learning two languages from birth. According to Annick De Houwer, in an article in The Handbook of Child Language, simultaneous bilingualism takes place in "children who are regularly addressed in two spoken languages from before the age of two and who continue to be regularly addressed in those languages up until the final stages" of language development. Both languages are acquired as first languages. This is in contrast to sequential bilingualism, in which the second language is learned not as a native language but a foreign language.

In psychology and philosophy, theory of mind (often abbreviated to ToM) is the capacity to understand other individuals by ascribing mental states to them. A theory of mind includes the understanding that others' beliefs, desires, intentions, emotions, and thoughts may be different from one's own. Possessing a functional theory of mind is crucial for success in everyday human social interactions. People utilize a theory of mind when analyzing, judging, and inferring other people's behaviors.

Theory of mind was first conceptualized by researchers evaluating the presence of theory of mind in animals. Today, theory of mind research also investigates factors affecting theory of mind in humans, such as whether drug and alcohol consumption, language development, cognitive delays, age, and culture can affect a person's capacity to display theory of mind.

Babbling is a stage in child development and a state in language acquisition during which an infant appears to be experimenting with uttering articulate sounds, but does not yet produce any recognizable words. Babbling begins shortly after birth and progresses through several stages as the infant's repertoire of sounds expands and vocalizations become more speech-like. Infants typically begin to produce recognizable words when they are around 12 months of age, though babbling may continue for some time afterward.

Babbling can be seen as a precursor to language development or simply as vocal experimentation. The physical structures involved in babbling are still being developed in the first year of a child's life. This continued physical development is responsible for some of the changes in abilities and variations of sound babies can produce. Abnormal developments such as certain medical conditions, developmental delays, and hearing impairments may interfere with a child's ability to babble normally. Though there is still disagreement about the uniqueness of language to humans, babbling is not unique to the human species.

Developmental language disorder (DLD) is identified when a child has problems with language development that continue into school age and beyond. The language problems have a significant impact on everyday social interactions or educational progress, and occur in the absence of autism spectrum disorder, intellectual disability, or a known biomedical condition. The most obvious problems are difficulties in using words and sentences to express meanings, but for many children, understanding of language (receptive language) is also a challenge. This may not be evident unless the child is given a formal assessment.

Recent work has moved toward standardising terms for children's language difficulties. In 2017, the CATALISE consortium recommended adopting "developmental language disorder" (DLD) for a subset of language disorder within the broader category of speech, language, and communication needs, with the aim of clearer communication, greater public awareness, and improved access to services. Earlier labels such as "developmental dysphasia" and "developmental aphasia" were discouraged because they suggest parallels with adult, brain-injury related conditions. The North American term "specific language impairment" (SLI) was also judged too narrow, as it focused on language in isolation and did not account for other difficulties that may co-occur.