Aims

(1) To determine the prevalence and detection of specific language impairment (SLI) in middle childhood.

(2) To identify the most common comorbid deficits associated with SLI in the educational, social, emotional and behavioural domains.

(3) To examine the association between key factors (e.g., language abilities, gender) and educational, social, emotional and behavioural outcomes in typical (non-SLI) children and children with SLI.

(4) To raise awareness of SLI in middle childhood and develop knowledge and understanding of SLI as children approach the primary-secondary school transfer.

Hypotheses

(1) SLI is a developmental condition and is subject to changes over time. We hypothesise that the prevalence of SLI amongst children in middle childhood in the ALSPAC sample would be beween 5 and 10%, with boys showing a higher prevalence than girls.

(2)SLI is associated with a range of comorbidities: deficit in pragmatic language skills, difficulties in literacy, numeracy and science learning, and a higher prevalence of emotional, behavioual and peer problems compared with their typically developing (TD) peers.

(3) Children with SLI, however, are just as likely as their TD peers to display prosocial behaviour.

Exposure variables

- Expressive language skills

- Receptive language skills

- Performance and verbal IQ

- Speech problem and speech therapy attendance

- Education provision and special education needs (SEN)

- Milestones in understandng and talking; speech and language development

- Gender

Outcome variables

- Conduct problems

- Hyperactivity

- Emotional symptoms

- Peer relations

- Prosocial behaviour

- General behaviour or personality problems

- Pragmatic language skills

- Reading skills

- Educational attainment in English, maths and science

Confounding variables

- Family history of speech and language problems

- Medical problems (epiliepsy)

- Developmental milestones and difficulties, eg fine and gross motor skills, social development, developmental delay, diagnosis of autism/ASD.

- Hearing impairment

- Number of other children in family

- Number of people living in the household

- First language

- Maternal education

- Parental employment

- Family income

- Age

- Ethnicity