In Sunday’s New York Times, there is an article discussing the links between temperament and anxiety. My discovery of the link between sleep duration and temperament originally published in 1981 was selected for re-publication in the Annual Progress in Child Psychiatry and Child Development by Chess and Thomas whose temperament research was referenced in the NYT piece. Basically, I discovered that 4- month-old infants with an easy temperament had long sleep durations and those with difficult temperaments had short sleep durations.
The same group of 4-month-old infants were studied again at age 3 years and the same results were found for the three year olds!
But there was very little individual stability of temperament traits between 4 months and three years. Some easy infants became difficult toddlers and some difficult infants became easy toddlers.
Sleep durations exactly predicted which direction the infants would take! The more sleep the infants had as toddlers the more likely they would remain easy or become easy. The less sleep the infants had as toddlers the more likely they would remain difficult or become difficult.
Sleep modulates temperament.
The NYT piece describes how infants with low sensory threshold or who are more sensitive or reactive are more likely to develop a brain that is associated with anxiety.
Here is an opinion based on my clinical experience and research. While it might be more difficult to establish healthy sleep habits in more sensitive infants (perhaps many of them are post colic) because they especially need dark and quiet sleeping environments and/or earlier bedtimes, the effort to get better quality sleep (even if extinction or graduated extinction is required) will pay off with a toddler who has an easier temperament and maybe less anxiety.
What are your thoughts?