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Sex differences in laterality are associated with reproduction in threespine stickleback

McLean, Stephanie; Morrell, Lesley J.


Stephanie McLean


Laterality, the partitioning of information processing into specific brain hemispheres, is widespread across animal taxa. Substantial unexplained variation in this trait exists, particularly between the sexes, despite multiple identified advantages of lateralization. Here, we demonstrate a relationship among laterality (mea-sured as directional biases), reproduction, and experience of mating and parenting. Using threespine sticklebacks (Gasterosteus aculea-tus), a species with uniparental male care, we showed that individuals of the caring sex (males) were more strongly lateralized than the non-caring sex (females) during reproduction and that laterality was reduced outside the breeding season in males. Additionally, males with experience of mating and parenting were more strongly lateralized than males without this experience. Our findings suggest that fitness-related behaviors that vary between the sexes, such as reproductive behaviors including courtship, spawning, and parenting, are significant but previously unidentified sources of variation in laterality.


McLean, S., & Morrell, L. J. (2021). Sex differences in laterality are associated with reproduction in threespine stickleback. The American naturalist, 197(6), 708-718.

Journal Article Type Article
Acceptance Date Dec 19, 2020
Online Publication Date Mar 1, 2021
Publication Date Jun 1, 2021
Deposit Date Mar 1, 2021
Publicly Available Date Mar 2, 2022
Journal American Naturalist
Print ISSN 0003-0147
Electronic ISSN 1537-5323
Publisher University of Chicago Press
Peer Reviewed Peer Reviewed
Volume 197
Issue 6
Pages 708-718
Keywords Cerebral lateralisation; Variation in laterality; Sex-differences; Parental care; Reproduction; Gasterosteus aculeatus
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©2020 The authors. All rights reserved. No part of this publication may be reproduced without the written permission of the copyright holder

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