Genetic and environmental influences on sleep quality, ability to settle, and crying duration in 2- and 5-month-old infants : A longitudinal twin study
Viktorsson, Charlotte ; Yahia, Ashraf LU
; Taylor, Mark J.
; Ronald, Angelica
; Tammimies, Kristiina
and Falck-Ytter, Terje
(2026)
In JCPP advances
6(1).
p.1-11
- Abstract
Background: Sleep and behavioral regulation are both vital for early healthy development. Yet, little is known about the relative contribution of genetic and environmental factors to early sleep and regulatory behaviors, or how these etiological influences may change during the first months of life. Methods: Genetic and environmental influences on sleep, settle, and crying behaviors at 2 and 5 months were examined in 998 twins, using a classical twin design. In addition, polygenic scores were derived for a range of sleep behaviors, as well as psychiatric and neurodevelopmental conditions. Results: Genetic influences (A) explained a large part of the variation in duration of crying at both 2 and 5 months (A = 0.29–0.70) and in settle... (More)
Background: Sleep and behavioral regulation are both vital for early healthy development. Yet, little is known about the relative contribution of genetic and environmental factors to early sleep and regulatory behaviors, or how these etiological influences may change during the first months of life. Methods: Genetic and environmental influences on sleep, settle, and crying behaviors at 2 and 5 months were examined in 998 twins, using a classical twin design. In addition, polygenic scores were derived for a range of sleep behaviors, as well as psychiatric and neurodevelopmental conditions. Results: Genetic influences (A) explained a large part of the variation in duration of crying at both 2 and 5 months (A = 0.29–0.70) and in settle ability at 5 months (A = 0.51–0.67). Shared environment (C) primarily influenced number of wakeups per night at both ages (C = 0.61–0.90) and settle ability at 2 months (C = 0.36–0.65). Longitudinal analyses suggested modest shared genetic influence on settle ability in the daytime across the ages (24%), and non-significant shared genetic estimates for ability to settle in the evening and at nighttime. There was moderate shared influence of shared environmental factors on number of wakeups per night (56%) and modest but significant shared genetic influence on crying duration in the evening and nighttime (17%–33%). Unique environmental effects were mostly specific to each age. Finally, autism polygenic score associated with longer crying duration in the evening at 2 months (β = 0.16, p =.002). Conclusions: Etiological influences tended to change from 2 to 5 months, reflecting a highly plastic period in infant brain development and in child-environment interactions.
(Less)
- author
- Viktorsson, Charlotte
; Yahia, Ashraf
LU
; Taylor, Mark J.
; Ronald, Angelica
; Tammimies, Kristiina
and Falck-Ytter, Terje
- publishing date
- 2026-03
- type
- Contribution to journal
- publication status
- published
- keywords
- crying, infants, settle ability, sleep, twins
- in
- JCPP advances
- volume
- 6
- issue
- 1
- article number
- e70023
- pages
- 1 - 11
- publisher
- John Wiley & Sons Inc.
- external identifiers
-
- pmid:41815772
- scopus:105009711150
- ISSN
- 2692-9384
- DOI
- 10.1002/jcv2.70023
- language
- English
- LU publication?
- no
- additional info
- Publisher Copyright: © 2025 The Author(s). JCPP Advances published by John Wiley & Sons Ltd on behalf of Association for Child and Adolescent Mental Health.
- id
- 4763c946-3d61-4882-a487-03d97119a7c0
- date added to LUP
- 2026-05-12 12:32:55
- date last changed
- 2026-06-09 14:21:05
@article{4763c946-3d61-4882-a487-03d97119a7c0,
abstract = {{<p>Background: Sleep and behavioral regulation are both vital for early healthy development. Yet, little is known about the relative contribution of genetic and environmental factors to early sleep and regulatory behaviors, or how these etiological influences may change during the first months of life. Methods: Genetic and environmental influences on sleep, settle, and crying behaviors at 2 and 5 months were examined in 998 twins, using a classical twin design. In addition, polygenic scores were derived for a range of sleep behaviors, as well as psychiatric and neurodevelopmental conditions. Results: Genetic influences (A) explained a large part of the variation in duration of crying at both 2 and 5 months (A = 0.29–0.70) and in settle ability at 5 months (A = 0.51–0.67). Shared environment (C) primarily influenced number of wakeups per night at both ages (C = 0.61–0.90) and settle ability at 2 months (C = 0.36–0.65). Longitudinal analyses suggested modest shared genetic influence on settle ability in the daytime across the ages (24%), and non-significant shared genetic estimates for ability to settle in the evening and at nighttime. There was moderate shared influence of shared environmental factors on number of wakeups per night (56%) and modest but significant shared genetic influence on crying duration in the evening and nighttime (17%–33%). Unique environmental effects were mostly specific to each age. Finally, autism polygenic score associated with longer crying duration in the evening at 2 months (β = 0.16, p =.002). Conclusions: Etiological influences tended to change from 2 to 5 months, reflecting a highly plastic period in infant brain development and in child-environment interactions.</p>}},
author = {{Viktorsson, Charlotte and Yahia, Ashraf and Taylor, Mark J. and Ronald, Angelica and Tammimies, Kristiina and Falck-Ytter, Terje}},
issn = {{2692-9384}},
keywords = {{crying; infants; settle ability; sleep; twins}},
language = {{eng}},
number = {{1}},
pages = {{1--11}},
publisher = {{John Wiley & Sons Inc.}},
series = {{JCPP advances}},
title = {{Genetic and environmental influences on sleep quality, ability to settle, and crying duration in 2- and 5-month-old infants : A longitudinal twin study}},
url = {{http://dx.doi.org/10.1002/jcv2.70023}},
doi = {{10.1002/jcv2.70023}},
volume = {{6}},
year = {{2026}},
}