Key takeaways: Temperament is a baby’s natural way of reacting to the world, such as how active, adaptable, intense, or sensitive they are. Researchers Thomas and Chess described traits that shape whether babies seem “easy,” “slow to warm up,” or “difficult.” Temperament isn’t caused by parenting, but a good fit between a baby’s temperament and caregiving helps babies thrive.
Some babies go with the flow; others react strongly to every change. Much of this is temperament.
What Is Temperament?
Temperament is a set of inborn traits that shape how a baby responds to people and situations. It’s partly biological and can change somewhat over time.
Classic Temperament Traits
In the New York Longitudinal Study, Thomas and Chess described nine traits:
- Activity level.
- Regularity of eating, sleeping, and other routines.
- Approach or withdrawal with new people and situations.
- Adaptability to change.
- Intensity of reactions.
- Mood: generally positive or negative.
- Persistence and attention span.
- Distractibility.
- Sensory threshold: sensitivity to noise, light, and touch.
Three General Styles
- Easy: regular, adaptable, mostly positive mood.
- Slow to warm up: cautious with new things, adapts over time.
- Difficult (or “spirited”): irregular, intense, slower to adapt.
Many babies don’t fit neatly into one group.
Goodness of Fit
Thomas and Chess emphasized “goodness of fit,” the match between a child’s temperament and their environment. Adjusting your approach can help:
- Sensitive babies: keep environments calm and introduce changes gradually.
- Active babies: offer plenty of safe movement.
- Slow-to-warm babies: give time with new people and places.
- Intense babies: stay calm and help them settle.
It’s Not Your Fault
Temperament isn’t caused by parenting. A fussier baby doesn’t mean you’re doing something wrong.
When to Ask for Help
If your baby’s crying, sleep, or feeding problems are overwhelming, talk to your pediatrician.
The Bottom Line
Every baby has a unique temperament. Understanding yours helps you respond in ways that fit your baby.
Want more support for your baby’s first year? My book, From First Breath to First Birthday, is available on Amazon.
Sources
- Thomas A, Chess S. Temperament and Development. Brunner/Mazel; 1977.
- American Academy of Pediatrics. How to understand your child’s temperament. HealthyChildren.org. https://www.healthychildren.org
- Rothbart MK. Temperament, development, and personality. Curr Dir Psychol Sci. 2007;16(4):207-212.
This article is for general education and is not a substitute for individualized medical advice. Always talk with your baby’s health care provider or your own provider about your specific situation. If you think your baby or you may have a medical emergency, call 911.
