Prevalence and developmental course of 'secret language'

Area of Science:

• Developmental Psychology
• Linguistics
• Twin Studies

Background:

• Children sometimes develop unique communication forms, termed 'secret language' or cryptophasia.
• The developmental trajectory and implications of cryptophasia, particularly in twins, require further investigation.

Purpose of the Study:

• To examine the prevalence and developmental course of 'secret language' in twins and singleton pairs.
• To identify factors associated with persistent use of private language in young children.

Main Methods:

• Systematic assessments of child pairs at 20 and 36 months of age.
• Categorization of 'secret language' into shared understanding and private language.
• Cognitive, language, and environmental assessments were conducted.

Main Results:

• 'Secret language' was more prevalent in twins than singletons and typically emerged in the second year of life.
• A subset of primarily male twins exhibited persistent private language at 36 months, associated with poorer cognitive/language skills and dependent relationships.
• Follow-up at age 6 indicated poor language outcomes for children who continued using private language without developing normal language skills.

Conclusions:

• Cryptophasia is often a transient developmental phase, particularly in twins.
• Persistent private language use in early childhood may be an indicator of developmental challenges.
• Early identification and intervention may be crucial for children exhibiting persistent cryptophasia.