Jean-Baptiste Leca, Ph.D.

Assistant Professor
Board of Governors Research Chair (Tier II)
Department of Psychology
University of Lethbridge
Canada

Current and main research activities

I study behavioral innovations and cultural traditions in non-human primates. This topic intrigues psychologists and biologists alike because culture is a social (rather than genetic) means by which traits can be inherited. I aim to shed light on how cultural behavioral patterns originate, spread, and are maintained or may change over time, by studying proximate (i.e., genetic, environmental, cognitive, demographic, social) and ultimate (i.e., adaptive, phylogenetic) influences.
My research projects address the biological, psychological and ecological foundations of behavioral traditions in Japanese macaques and long-tailed macaques in order to better understand the role of cultural processes in human evolution. In a nutshell, I am interested in the hows and whys of cultural behaviors in monkeys.


While most primate cultures are considered adaptive – like chimpanzee tool use – I explore the proximate and ultimate causes of non-adaptive or questionably adaptive behavioral traditions. By focusing on such exceptions to the rule, my research contributes to further our understanding of evolutionary processes and the variety of behavioral patterns they produce.

Material culture in long-tailed macaques


Currently, my research team members and I are developing three complementary projects that explore group-specific (and thus potentially cultural) behavioral patterns in free-ranging Balinese long-tailed macaques.



More specifically, we are investigating the development, mechanisms and possible functional components of:


  • stone handling/play
  • eye covering play
  • object robbing and object/food bartering practice
  • as well as complex extractive foraging (e.g., coconut bashing) and tool-assisted foraging in this primate species.

Non-conceptive sex in Japanese macaques


Simultaneously, I am continuing to study non-conceptive (socio-)sexual behaviors in female and male Japanese macaques from a longitudinal and intergroup comparative perspective:


  • immature play mounting

  • female-male mounting

  • male masturbation

  • monkey-deer mounting

  • social dynamics of all-male groups


My long-term goal is to extend my research on non-adaptive cultural behaviors to other macaque species and use these comparative analyses to model the forces that have shaped our own culture during the course of human evolution. In doing so, I will investigate how seemingly non-adaptive behaviors may lead to adaptive outcomes for the individual, the group, and the species.


The following items summarize these different ongoing research projects.


STONE-HANDLING/PLAY CULTURE
IN JAPANESE MACAQUES AND BALINESE LONG-TAILED MACAQUES

Stone handling/play

(Japanese macaques)
For further details, please CLICK on the picture above
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Stone handling/play
(Balinese long-tailed macaques)
For further details, please CLICK on the picture above

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COMPLEX EXTRACTIVE FORAGING CULTURE IN BALINESE LONG-TAILED MACAQUES


Coconut bashing

(Balinese long-tailed macaques)

For further details, please CLICK on the picture above

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Crab-foraging

(Balinese long-tailed macaques)

For further details, please CLICK on the picture above

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EYE-COVERING PLAY CULTURE IN BALINESE LONG-TAILED MACAQUES

Eye-covering play
(Balinese long-tailed macaques)
For further details, please CLICK on the picture above
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OBJECT ROBBING & OBJECT/FOOD BARTERING CULTURE

IN BALINESE LONG-TAILED MACAQUES


Object robbing
(Balinese long-tailed macaques)
For further details, please CLICK on the picture above


Robbing and bartering in Balinese long-tailed macaques, filmed by the BBC 2 - Natural History Unit:

"World's Sneakiest Animals" series, BBC (January 2016)  [VIDEO]

"Natural Born Hustlers" series, PBS-Nature (January 2016)  [VIDEO]

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Object robbing
(Balinese long-tailed macaques)
For further details, please CLICK on the picture above


Robbing and bartering in Balinese long-tailed macaques, filmed by the BBC 2 - Natural History Unit:

"World's Sneakiest Animals" series, BBC (January 2016)  [VIDEO]

"Natural Born Hustlers" series, PBS-Nature (January 2016)  [VIDEO]

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FISH-EATING CULTURE IN JAPANESE MACAQUES

Fish eating

(Japanese macaques)
For further details, please CLICK on the picture above
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DENTAL FLOSSING INNOVATION IN JAPANESE MACAQUES

Dental flossing
(Japanese macaques)
For further details, please CLICK on the picture above
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NON-CONCEPTIVE SEX CULTURE IN JAPANESE MACAQUES


Female homosexual behavior

(Japanese macaques)
For further details, please CLICK on the picture above
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Female-male mounting
(Japanese macaques)
For further details, please CLICK on the picture above
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Male homosexual behavior in all-male groups

(Japanese macaques)

For further details, please CLICK on the picture above

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Monkey-deer mounting
(Japanese macaques)
For further details, please CLICK on the picture above