Impulsivity and quantity preference in dogs

Jeff Stevens

Canine Cognition and Human Interaction Lab
University of Nebraska-Lincoln
dogcog.unl.edu

Perceptions of Impulsivity

Owner perceptions of dog impulsivity

Research Question

Do owner perceptions of dog impulsivity predict impulsivity in a behavioral task?

Based on and replicated Brady et al., 2018

Stevens et al. 2022, Animal Behavior & Cognition

Measuring owner perceptions

Dog Impulsivity Assessment Scale (DIAS)

Behavioral regulation + aggression + responsiveness

Wright et al., 2011

Stevens et al. 2022, Animal Behavior & Cognition

Measuring spatial impulsivity

Stevens et al. 2022, Animal Behavior & Cognition

Study design

Study 1

• At UNL CCHIL
• Recruited 117 dogs
• 65 dogs completed testing/owners completed DIAS

Study 2

• At dog daycare
• Recruited 103 dogs
• 49 dogs completed testing/owners completed DIAS

Stevens et al. 2022, Animal Behavior & Cognition

Perception vs. behavior

Stevens et al. 2022, Animal Behavior & Cognition

Discussion

• Owners not good at predicting dog impulsivity

• Did not replicate Brady et al., 2018

  • British know their dogs better than Americans
  • Poor attempt at replication
  • Different dog populations (breeds, neuter status)
  • Different owner populations
  • Less than robust methods in original study

Impulsivity as a trait

Impulsivity as a trait in dogs

Research Question

Is impulsivity a behavioral trait in dogs?

• Do dogs’ impulsivity levels correlate across tasks?
• Do dogs’ impulsivity levels correlate with owner perceptions?

Barela et al. 2024, Journal of Comparative Psychology

Systematic review and meta-analysis

• Searched 9,900 records from Scopus, Web of Science, and PsychINFO
• 13 articles conducted correlations between impulsivity tasks and/or between the Dog Impulsivity Assessment Scale (DIAS) and behavioral tasks

Barela et al. 2024, Journal of Comparative Psychology

Tasks

• A-not-B Barrier
• A-not-B Cup
• Box
• Buzzer
• Cylinder
• Delay Discounting
• Detour Fence

• Leash
• Middle Cup
• Sit-Stay
• Social Inhibition
• Spatial Impulsivity
• Wait-for-Treat

Barela et al. 2024, Journal of Comparative Psychology

Task pairs (N=29)

Barela et al. 2024, Journal of Comparative Psychology

DIAS and tasks (N=15)

Barela et al. 2024, Journal of Comparative Psychology

Discussion

• Impulsivity does not correlate across tasks

• Impulsivity sometimes correlations with DIAS

• Impulsivity does not seem to be a behavioral trait

  • Similar to other species, including humans

  • Impulsivity is likely domain-specific

  • Maybe measure of perception (DIAS) isn’t capturing impulsivity

Quantity preference

Dog quantity preferences

Research Question

What are the relative contributions of numerical difference and ratio in determining dog quantity preferences?

Food preference task

What drives preference?

Weber’s Law

Detecting differences in stimuli depends on relative magnitude

Numerical ratio

Key signature of Weber’s law

Ratio = small / large

Small	Large	Ratio
1	2	0.50
2	4	0.50
1	3	0.33
2	6	0.33

Small	Large	Ratio
1	2	0.50
2	4	0.50
1	3	0.33
2	6	0.33

Numerical difference/distance/disparity

Not related to Weber’s law

Difference = large − small

Small	Large	Difference
1	2	1
2	4	2
1	3	2
2	6	4

Small	Large	Difference
1	2	1
2	4	2
1	3	2
2	6	4

Previous work on difference and ratio

Study	Ratio effects	Difference effects
Ward & Smuts 2007	Yes	Yes
Baker et al. 2012	Yes	Not tested
Miletto Petrazzini & Wynn 2016	Yes	Not tested
Aulet et al. 2019	Yes	Not tested
Rivas-Blanco et al. 2020	Yes	Not tested

Subjects

• Seven dogs from local dog daycare completed all sessions
  • 2:5 male:female (all spayed/neutered)
  • Two goldendoodles, one golden retriever, one collie, three mixes
  • 1-3 years old
  • 12-78 lbs

deBoer et al. PsyArXiv

Set-up

deBoer et al. PsyArXiv

Procedures

• Sessions consisted of warm-up trials, experimental trials, and jackpot trials
• Ten sessions per subject

deBoer et al. PsyArXiv

Numerical pairs

Small	Large	Difference	Ratio
1	3	2	0.33
2	6	4	0.33
3	9	6	0.33
1	2	1	0.50
2	4	2	0.50
4	8	4	0.50
2	3	1	0.67
4	6	2	0.67
8	12	4	0.67

Small	Large	Difference	Ratio
1	3	2	0.33
2	6	4	0.33
3	9	6	0.33
1	2	1	0.50
2	4	2	0.50
4	8	4	0.50
2	3	1	0.67
4	6	2	0.67
8	12	4	0.67

deBoer et al. PsyArXiv

Difference or ratio

deBoer et al. PsyArXiv

Difference and ratio

Model	BF
choice ~ (1 | dog_id)
choice ~ diff + (1 | dog_id)	2,531.3
choice ~ ratio + (1 | dog_id)	15.9
choice ~ diff + ratio + (1 | dog_id)	481.4
choice ~ diff * ratio + (1 | dog_id)	19.8

Model	BF
choice ~ (1 | dog_id)
choice ~ diff + (1 | dog_id)	2,531.3
choice ~ ratio + (1 | dog_id)	15.9
choice ~ diff + ratio + (1 | dog_id)	481.4
choice ~ diff * ratio + (1 | dog_id)	19.8

deBoer et al. PsyArXiv

Summary

• Both difference and ratio predict numerical preference when analyzed separately

• But only difference predicts when analyzed together

deBoer et al. PsyArXiv

Previous preference work

Ward & Smuts 2007

Previous discrimination work

Rivas-Blanco et al. 2020

Discussion

• Revisit ubiquity of Weber’s Law

• Explore other properties of Weber’s Law

• Include difference in models and design studies to test difference effects

Lessons Learned

Replicability

• Increase sample sizes
• Conduct more replications (within and between labs)
• Increase robustness and reproducibility of analyses
• Post data publicly
• Provide more and consistent info on owners
• Consider populations of owners and dogs

Site differences

Construct validity

• Revisit theoretical constructs
• Connect to work on other species
• Focus on reliable measures

Credibility

• Question dogma
• Be open to alternative factors at play
• Use strong inference and triangulation
• Analyze other people’s data

Thank you!

Jessica
Barela Hunter
DeBoer Hannah
Fitzpatrick Anwyn
Gatesy-Davis London
Wolff

jstevens5@unl.edu dogcog.unl.edu @unl_cchil