Introduction

Language and communicative competence provide critical tools for learning, engaging in social relationships, and behaviour and emotion regulation from infancy onward. This report describes the evolution of language development in the first five years of life and its interrelationship with psychosocial and emotional development and disorder across the life span. Implications for prevention, intervention, education and public policy will also be discussed.

Subject Relevance

Two domains are considered under the rubric of language: structural language and pragmatic communication. Structural language skills encompass the sounds of language (phonology), vocabulary (semantics), grammar (syntax and morphosyntax), narrative discourse, and auditory verbal information processing. Pragmatic language skills include behaviours such as conversational or other communicative turn-taking, making good use of gestures and maintaining eye contact. As well as these specific aspects of language and communication, children must be able to both express their thoughts (expressive language) and understand those of others (receptive language) in both social and learning situations.

When children have difficulty understanding others and expressing themselves, it is not surprising that psychosocial and emotional adjustment problems ensue. Conversely, a relatively large proportion of school-aged children who have psychosocial and emotional disorders often have problems with language and communication (Cohen, 2001).

Problems

It can be difficult to separate psychosocial and emotional problems from problems with language and communication. Language impairments can be subtle and go undetected unless a formal assessment is done (Cohen, Barwick, Horodezky, Vallance & Im, 1998). For instance, Kaler and Kopp (1990) showed that toddlers' compliance with adult commands was related to how well they understood language. In another study, Evans (1996) found that many preschoolers described as shy, reticent or inhibited had language impairments that interfered with forming and maintaining friendships. Children with language impairments had difficulty entering into peer group conversations and were then excluded, giving them less opportunity to learn and practice the social skills they needed for peer interaction. Failure to identify and treat such problems can have serious consequences.

Research Context

Language development and impairment and their association with psychosocial and emotional development and disorder have been examined in cross-sectional and longitudinal studies of community and clinic (both speech-language clinic and mental- health clinic) samples ranging from infancy through adolescence. In these studies, aspects of language and skills with which language and communication are associated have been examined.

Key Research Questions

Key research questions include:
(1) What is the pattern of development of communication and language in the first five years of life?
(2) What is the prevalence of language and communicative impairment in the general population between birth and age five?
(3) With which psychosocial and emotional disorders are language impairments associated?
(4) Are there other developmental functions associated with language impairment other than psychosocial and emotional disorders?
(5) What is the outcome for children with communication and language impairments?
(6) What causal factors contribute to an association of language impairment with psychosocial and emotional development?
(7) Is there something specific about language as a focus for study?
(8) What are the best ways of treating language impairments?

Recent Research Results

In the first five years of life, the evolution of communication can be divided into three periods (Adamson & Chance, 1998). The first period begins at birth when infants communicate through their cries, gazes, vocalizations and early gestures. These early communicative behaviours are not intentional, but set the stage for later intentional communication. In the second period, from six to 18 months, infants’ communicative engagement with adults becomes intentional. A major turning point is the appearance of joint attention (Bakeman & Adamson, 1984), which involves infants coordinating visual attention with that of another person regarding objects and events (Mundy & Gomes, 1998). In the third period, from 18 months onward, language overtakes action as children’s primary means of learning and communication. For instance, preschoolers can engage in conversations about emotions that take into account another’s affective state (Dunn, Brown, Slomkowski, Tesla & Youngblade, 1991), can use language for self-control (Berk & Potts, 1991) and have the capacity to negotiate verbally (Bloomquist, August, Cohen, Doyle & Everhart, 1997).

It is estimated that 8 to 12% of preschool children have some form of language impairment (National Institute of Deafness and Other Communication Disorders, 1995). Most children are not identified until two to three years of age when they fail to speak. Further, approximately half of preschool- and school-aged children referred to mental-health services or placed in special classes have language impairments or language-related learning disabilities (Cohen, et al., 1998). There are no data on the prevalence of preverbal communication problems in infants, although the availability of new screening tools now makes this possible (Wetherby & Prizant, 2001).

A range of psychosocial and emotional disorders has been associated with language impairment. In infants, problems with emotion and behaviour regulation (e.g. difficulty being soothed, eating and sleeping) are most common (Barwick, Cohen, Horodezky, Lojkasek, 2004). Physical and expressive vocabulary are associated with spoken vocabulary as early as 19 months of age (Dionne, Tremblay, Boivin, Laplante & Persusse, 2003). From the preschool years, the most common diagnosis among children with language impairments in the community who are referred to speech-language and mental-health clinics is Attention Deficit (Hyperactivity) Disorder (Beitchman, Wilson, Johnson, Atkinson, Young, Adlaf, et al., 1986; Cantwell & Baker, 1991; Cohen, Menna, Vallance, Barwick, Im & Horodezky, 1998). Language impairments do not exist in isolation and from early childhood, language development is also linked with cognition, social cognition and motor skills (Cohen, Barwick, et al., 1998; Cohen, Menna, et al., 1998).

Longitudinal studies yield sobering findings for children with language impairments (Cohen, 2002). Language and communication impairments are consistently related to learning and psychosocial and emotional disorder from infancy to adolescence (Beitchman, Wilson, Johnson, Atkinson, Young, Adlaf, et al., 2001; Cantwell & Baker, 1991; Stattin & Klackenberg-Lasson, 1993; Williams & Mcgee, 1996). The prognosis is poorest for children who have difficulties in understanding language or in multiple areas of language that continue beyond the age of five years (Beitchman, et al., 2001; Whitehurst & Fischel, 1994).

Both genetic and environmental factors contribute to language and psychosocial and emotional development (Rutter, 2003). Children who are poor communicators do not send clear messages and therefore may be difficult to read and respond to appropriately. The amount and kind of language stimulation at home (Hart & Risley, 1995) and family stresses such as child abuse (Coster & Cicchetti, 1993) also contribute to children’s language development.

The question still remains as to whether there is something specific about language as a focus for study. On the one hand, language may be just one of a range of developmental functions caused by a common underlying factor (Hill, 2001). On the other hand, language may have a central role to play in the development of psychosocial and emotional disorders in that internalized language and verbally mediated rules play an important role in both self-control and achievement across domains (Denckla, 1996).

Conclusions

From infancy onward, language and psychosocial and emotional development are interrelated. Communication begins in the very first days of life. Potential problems that begin in relationships with parents can ultimately spiral as children enter school and have difficulty learning and getting along with teachers and peers. Even mild language impairments can have an impact on the course of development. Outcomes are worsened by the presence of co-occurring environmental stresses. Because language competence is critical for both school readiness and psychosocial and emotional adjustment, problems with language and communication can set a child on a maladaptive trajectory throughout life (Moffitt, 1993). Language problems can be subtle and may be overlooked in learning and therapeutic situations.1 Therefore, identification and assessment of language disorders, and intervention, are important in the early years, setting the stage for later competence in a broad range of areas.

Implications for Policy and Services

Starting from infancy, routine assessment of language and communication skills and provision of interventions are essential preventive undertakings. This is important because interventions during infancy or the preschool years can have a significant impact on child outcomes (Halpern, 2000). Once identified, creating a comprehensive profile of communication, language, cognitive and psychosocial and emotional abilities is crucial to planning such preventive interventions. There has been a move away from one-to-one clinic-based therapy to a focus on functional language in naturalistic environments (McLean & Cripe, 1997). Interministerial and multidisciplinary integration is required because of the implications that undiagnosed language impairments have for health, mental health, child care, education and the youth justice system. Information on the nature of language impairments, and their impact on academic and psychosocial and emotional functioning, should be available to parents and be part of the curriculum for professionals working with children. This includes pediatricians, family practitioners, speech/language pathologists, educators, early childhood educators and mental-health practitioners.