Speech Delay and Family History

Speech delay does run in families. A toddler whose parent or sibling talked late is more likely to talk late, and the explanation lies far more in what children inherit than in how they are raised. A family history raises the odds without settling anything for one child, so it is a reason to watch closely and ask.

What you’ll learn

• What research on families and late talking has found
• Other speech, language and hearing differences that run in families
• What a family history can’t tell you about one child
• What to write down, and why family history is a reason to ask

Does Speech Delay Run in Families?

Late talking, which clinicians call late language emergence, means a toddler is slow to start using words, and it runs strongly in families. In its clinical guidance, the American Speech-Language-Hearing Association (ASHA) states that toddlers who talk late are more likely to have a parent who talked late as well. ASHA also counts family history as a risk factor, and asking about it is a standard part of a speech evaluation.

ASHA’s figures come from a population study that followed 1,766 children over time. At 24 months, 23 percent of the children with a family history of late talking were late talkers themselves, against 12 percent of the children with no such history, so late talking turned up about twice as often where it already ran in the family.

Two other things predicted late talking at 24 months in the same study: being a boy, and being born early or small, meaning before 37 weeks of pregnancy or at less than 85 percent of the expected birth weight.

How Much of Late Talking Comes From Genes?

Research on twins points toward genes. In a study of more than 3,000 pairs of 2-year-old twins, published in the journal Nature Neuroscience, genes played a much larger part among the children with the smallest vocabularies than the shared environment did, meaning everything that twins growing up in one family have in common. The result describes groups of children, so it says nothing about how much of one child’s talking comes from genes.

The population study of 1,766 children looked at home life as well, and late talking at 24 months was not linked to parenting practices, to parents’ mental health or to how the family functioned. Siblings with the same parents can also start talking on very different schedules, one on time and one late, and that would be hard to explain if the cause lay in how they were raised.

Everyday conversation still matters, since back-and-forth talk supports language, but the reason late talking clusters in families lies mainly in what children inherit, and parenting creates none of the causes of speech delay that clinicians can identify.

Other Speech and Language Differences That Run in Families

Late talking is one of several differences that can follow family lines, and each of these four is worth mentioning at an appointment if it appears in the family.

• Developmental language disorder (DLD). DLD is a lasting difficulty learning and using language that another condition, such as hearing loss or autism, doesn’t explain. The National Institute on Deafness and Other Communication Disorders (NIDCD) reports that 50 to 70 percent of children with DLD have at least one family member with the disorder, and ASHA notes that several genes, not one, contribute to it.
• Trouble saying speech sounds clearly. ASHA reports that children whose parents or siblings have speech or language difficulties are more likely to have a speech sound disorder, which affects how clearly a child produces the sounds of speech.
• Stuttering. NIDCD says developmental stuttering, the kind that begins in childhood, may run in families, and that genetic factors contribute to it.
• Hearing loss. The Centers for Disease Control and Prevention (CDC) says about 4 out of 5 babies with hearing loss have a genetic cause, so a family history of hearing loss is worth mentioning too.

A family history of any of these raises the likelihood across a group of children without meaning that a particular child has the condition, and a family with no history at all can still have a child whose talking needs a closer look. NIDCD describes DLD as a difference in how the brain develops, arising from complex interactions between genes and environment, and says the exact causes of those brain differences are unknown.

What Family History Can’t Predict About Your Child

A family history describes odds across groups of children, not the path of one child. A review published in the Journal of Speech, Language, and Hearing Research, which pooled 20 samples covering 2,134 late talkers, found that family history did not predict later expressive language, meaning the words a late talker goes on to use, and neither did being a boy. A toddler’s own vocabulary and understanding of language, called receptive language, were among the things that did.

Nobody can tell early on how late talking will turn out for one toddler, with or without a family history. In long-term studies reviewed by ASHA, about half of late talkers catch up without help, while 30 to 50 percent do not, and clinicians cannot predict in advance which children will need support. ASHA explains why: at the start, a late talker who goes on to catch up and one who does not look alike, and the difference can only be seen afterward.

The same is true of being a boy. ASHA reports that boys are about three times as likely as girls to talk late, and the U.S. Preventive Services Task Force (USPSTF) reports that boys are more than twice as likely as girls to have a speech or language disorder. A difference that holds across groups of children still can’t show how one boy’s talking will go, so being a boy is no reason to put off a question about his speech.

From clinical practice

“His uncle talked late, and he turned out fine.” A story like that travels with late talking through many families. It is told kindly, and because it seems to show how late talking ends, it can persuade a family to hold off on calling anyone.

In the research, the same family history is a reason to keep a closer eye and to ask. One relative’s outcome says nothing about how a different child’s language will develop. The uncle’s story still has a use. It belongs in the family history given at an evaluation, alongside whatever the family has noticed in the child.

Watching Closely When Late Talking Runs in the Family

Keeping a closer eye starts with writing a few things down. The American Academy of Pediatrics advises sharing any family history of speech and language disorders when you raise a concern, because some of these disorders have a strong genetic component, and the details are easier to give when they are already on paper:

• Who in the family talked late, on either side, and how late, if anyone remembers
• Anyone who had trouble saying speech sounds, who stuttered, or who was told they had a language disorder
• Any hearing loss in the family, particularly in childhood
• The words your child says and understands now, with the date beside them

Your child’s own hearing deserves a check as well. Hearing is part of any speech and language evaluation, since hearing that comes and goes with repeated ear infections can affect how language develops. A pass at birth does not settle the question either, because NIDCD notes that hearing loss can develop after a baby passes the newborn test. NIDCD also says hearing is often tested as part of a speech and language evaluation, since a hearing problem can affect speech and language development.

When a clinician is following a toddler who talks late, ASHA’s guidance is to look again at regular intervals, such as every 6 months. A dated record of new words, first two-word phrases and what your child understands gives each of those rechecks a clear starting point.

Family History as a Reason to Ask, Not to Wait

A family history of late talking is a reason to raise any concern you have, whenever you have it, and not a reason to wait and see. Nobody can tell ahead of time which late talkers will need support, and asking costs little, because the evaluation through a state’s early intervention program is carried out at public expense.

Guidance from national bodies points the same way. The CDC built its Learn the Signs, Act Early program to avoid a wait-and-see approach, so that any missed milestone or concern leads to a conversation or action, and the USPSTF tells clinicians to listen to any concern a caregiver raises about a child’s speech and language.

You don’t need a referral to contact your state’s early intervention program, because Part C of the Individuals with Disabilities Education Act (IDEA), the federal special education law, obliges every state to accept a referral made by a parent. If your pediatrician sees no reason for concern and you still have one, the American Academy of Pediatrics’ advice to parents is to trust that instinct and get a second opinion.

For the wider picture, there is more on what speech delay is and on when to seek help, and the way talking develops across early childhood is set out in speech and language development.

Common Questions From Parents

Is Speech Delay Genetic?

Genes play a large part, though not the only one. Twin research on 2-year-olds found genes counted for far more than the shared home among the children with the fewest words, and NIDCD says developmental language disorder arises from genes and environment acting together.

My Partner Talked Late. Does That Mean Our Child Will?

Not necessarily. In the study ASHA cites, late talking was about twice as common among children with a family history of it, but a group figure can’t tell anyone what one child will do. It is a reason to keep notes and mention it.

Are Boys More Likely to Talk Late Than Girls?

Yes, as a group: late talking shows up about three times as often in boys as in girls, according to ASHA. The figure says nothing about one particular boy, and in a large review, being a boy did not predict the words late talkers used later.

Does a Sibling’s Speech Delay Change Anything for the Next Child?

Where a sibling talked late, late talking becomes substantially more likely across a group, and ASHA links siblings’ speech or language difficulties to speech sound disorders. Siblings still talk on different schedules, so an older child’s history is worth mentioning, not a forecast.

Should Family History Change When We Ask for an Evaluation?

It is a reason to ask when a concern comes up, not to wait. Nobody can tell early which late talkers will need support, and early intervention programs accept referrals straight from parents, so mention the family history when you call.

Did I Pass This on to My Child?

Late talking follows family lines far more than parenting, and nobody chooses the genes a child receives. A large study found no link between late talking at 24 months and parenting practices, so a trait carried in families is not a parenting choice.

Reviewed by Monica d’Errico-Franklin, M.S., CCC-SLP

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