Early temperament and negative reactivity in boys with fragile X syndrome.
Three-year-old boys with fragile X show less sadness than peers, so skip the ‘moody’ label and focus assessment on attention and self-control.
01Research in Context
What this study did
Researchers watched 3-year-old boys with fragile X syndrome during play and snack time. They also asked parents to fill out a standard temperament survey.
They compared the boys to typically developing peers of the same age. The team looked for signs of sadness, anger, and general distress.
What they found
The boys with fragile X showed less sadness than their peers. Parents and observers both noted the same pattern.
Anger and distress levels were no different between the groups. Early temperament did not match the later behavior problems often seen in older boys with the syndrome.
How this fits with other research
Eussen et al. (2016) later tested boys aged 3-7 with fragile X. They found lower self-control and higher shyness, but sadness was not the key issue. The 2008 study set the baseline that the 2016 work then expanded.
Luckasson et al. (2020) tracked the same children for three years. ADHD symptoms predicted later autism-like social problems, not early sadness. The 2008 snapshot fits early in this longer timeline.
Wynne et al. (1988) described universal hyperactivity and anxiety in fragile X males. The 2008 data refine that picture: at age 3, sadness is actually lower, so later mood problems likely emerge after the toddler period.
Why it matters
When you assess a preschool boy with fragile X, do not assume he will look sad or angry. Use norm-referenced tools and watch real-time behavior instead of relying on older clinical lore. Target self-regulation and attention skills early, because those—not mood—are already off track and will shape later social and adaptive gains.
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02At a glance
03Original abstract
BACKGROUND: The phenotype of children and adults with fragile X syndrome (FXS) includes a number of problem behaviours such as inattention, social anxiety and aggressive outbursts. However, very little work has been conducted with young children with FXS less than 5 years of age to examine the developmental pathway of problem behaviours in this population and to determine if later occurring problem behaviours may be rooted in early appearing temperament profiles. METHODS: Parent ratings and laboratory-based behavioural observations of negative reactivity were examined in 25 3-year-old boys with FXS and compared with 64 typically developing boys matched on age. RESULTS: Compared with the typically developing group, boys with FXS were rated by their parents as exhibiting less anger and sadness on the Child Behaviour Questionnaire (CBQ), and they showed less facial sadness on the Laboratory Temperament Assessment Battery (Lab-TAB). No group differences were found on the Lab-TAB measures of distress vocalisations, bodily struggle, and facial anger; and anger peaked in the middle of the arm restraint episode for both groups. For boys with FXS, mental age was moderately positively correlated, and autistic behaviour was moderately negatively correlated, with sadness scores from the CBQ. CONCLUSIONS: Our results show different behavioural profiles in very young children with FXS than reported in older-aged children with FXS which implies that temperamental differences and elevated problem behaviours reported in older-aged children with FXS may not be rooted in early temperament. This information is important to develop the phenotype of early development in FXS to facilitate early identification and treatment.
Journal of intellectual disability research : JIDR, 2008 · doi:10.1111/j.1365-2788.2008.01074.x