When a bigger brain is better: The case of bee olfactory learning

C Coline Monchanin (Univ Toulouse, CNRS, Centre de Recherche sur la Cognition Animale) T Tamara Gómez-Moracho (Univ Toulouse, CNRS, Centre de Recherche sur la Cognition Animale) C Cristian Pasquaretta (Univ Toulouse, CNRS, Centre de Recherche sur la Cognition Animale) A Alexis Buatois (Department of Environmental Toxicology, Eawag, Swiss Federal Institute of Aquatic Science and Technology) L Louise Bestea (Univ Toulouse, CNRS, Centre de Recherche sur la Cognition Animale) P Paul Marchal (INSERM U1314, CNRS UMR5284, Institut NeuroMyoGene, MeLiS) P Philipp D. Lösel (Department of Materials Physics, Research School of Physics, The Australian National University) R Renaud Lebrun (Institut des Sciences de l’Evolution de Montpellier, CC64, Université de Montpellier) F Fabrice Lihoreau (Institut des Sciences de l’Evolution de Montpellier, CC64, Université de Montpellier) A Andrew B. Barron (School of Natural Sciences, Macquarie University) J Jean-Marc Devaud (Univ Toulouse, CNRS, Centre de Recherche sur la Cognition Animale) M Mathieu Lihoreau (Univ Toulouse, CNRS, Centre de Recherche sur la Cognition Animale)

Abstract

Whether bigger brains provide enhanced cognitive capacities is a long-lasting and controversial question. While big brains may not be required for producing sophisticated behavior, they could facilitate information processing and memory storage. Here, we report a positive relationship between head size and learning performance in two model bee species, using data from 2,141 individuals. Among honey bees, head size varied by about 30%, and those with larger heads showed higher olfactory learning performance for associative tasks that varied in difficulty. Microcomputed tomography measures indicated that this relationship was linked to brain size variation: The best odor learners had the largest antennal lobes. We made similar observations in bumblebees, suggesting that natural brain size variation is associated with individual cognitive variation in these social bees.

Article Details

Volume / Issue Vol. 123, Issue 17
Published April 28, 2026
ISSN 0027-8424
Publisher National Academy of Sciences

Authors (12)

C

Coline Monchanin

Univ Toulouse, CNRS, Centre de Recherche sur la Cognition Animale

T

Tamara Gómez-Moracho

Univ Toulouse, CNRS, Centre de Recherche sur la Cognition Animale

C

Cristian Pasquaretta

Univ Toulouse, CNRS, Centre de Recherche sur la Cognition Animale

A

Alexis Buatois

Department of Environmental Toxicology, Eawag, Swiss Federal Institute of Aquatic Science and Technology

L

Louise Bestea

Univ Toulouse, CNRS, Centre de Recherche sur la Cognition Animale

P

Paul Marchal

INSERM U1314, CNRS UMR5284, Institut NeuroMyoGene, MeLiS

P

Philipp D. Lösel

Department of Materials Physics, Research School of Physics, The Australian National University

R

Renaud Lebrun

Institut des Sciences de l’Evolution de Montpellier, CC64, Université de Montpellier

F

Fabrice Lihoreau

Institut des Sciences de l’Evolution de Montpellier, CC64, Université de Montpellier

A

Andrew B. Barron

School of Natural Sciences, Macquarie University

J

Jean-Marc Devaud

Univ Toulouse, CNRS, Centre de Recherche sur la Cognition Animale

M

Mathieu Lihoreau

Univ Toulouse, CNRS, Centre de Recherche sur la Cognition Animale