Abnormal repetitive behaviour and exposure to negative experiences in rhesus monkeys
Data files
Feb 04, 2026 version files 81.52 KB
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Mason_et_al._2025_with_anonymized_cage_and_no_Monkey_ID.xlsx
74.12 KB
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README.md
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Abstract
We tested the hypothesis that, in rhesus macaques used in biomedical research, the performance of abnormal repetitive behaviours (ARBs; e.g. pacing, hair-plucking, eye-poking) reflects the cumulative burden of negative experiences. For 240 macaques living in two US National Primate Centres, we did this by cataloguing, weighing, and summing exposure to 12 types of negative event or practice (two current, ten past), over animals' entire lifespans; and then assessing their aggregated impact on current behaviour. When all recorded forms of ARB were pooled into one measure, the hypothesis was strongly supported at one facility: Pooled ARB increased with Lifetime Negative Experience Scores in a dose-response type manner, and reflected the combined effects of both Current and Past Negative Experiences. At the other facility, Current Negative Experience Scores had no apparent impact on Pooled ARB; however, Past Negative Experience Scores were still highly predictive. This approach, inspired by psychological research on humans, adds to growing evidence that ARBs can reflect the cumulative impact of the number and severity of negative experiences, past and potentially present.
Dataset DOI: 10.5061/dryad.j3tx95xvt
Description of the data and file structure
Abnormal Repetitive Behaviour (ARB) data: data were collected via scans. Pacing, ‘rocking+’ and hair-plucking were the main ARBs observed. For analysis, pacing and rocking+ were combined as 'motor ARB'. All recorded ARBs (including rare forms not falling into the three main categories) were also pooled for further analysis: Pooled ARB. Data shared here are counts of ARB presence. The number of scans per subject is also supplied.
For negative experiences over the lifespan, we identified 12 types of challenge (events or facility practices likely to induce negative affect). Two pertained to current housing: an adverse cage location (low, near the door); and being singly-caged. Ten (extracted from facility records) pertained to past experiences: maternal loss in infancy; being born and raised indoors; living indoors; spending time singly-caged; being relocated; being aggressed by a cagemate; losing a cagemate; involvement in research projects; health events (including research procedures); and spending time in hospital.
To capture variation in aversiveness, every monkey was scored (blind to their behavioural data) between 0 and 1 for each challenge (where 0 is best for welfare, 1 is worst). For robustness, for 10 of the items we used two methods for this, varying in how differential experiences were weighted: a 'min-max' method divided a subject's scores by the dataset's greatest value for that challenge; and a 'quantiles' method scored each subjects categorically by ranks (typically quartiles) for each challenge. The two items pertaining to infancy (age when separated from mother; type of indoor/outdoor reading facility) were always scored 0-1 based on categories. All 22 scores are shared here. (Raw values are not shared for reasons of confidentiality).
These scores were totalled to create two Lifetime Negative Experience Scores (maximum 12). Current Negative Experience and Past Negative Experience Scores (respective maxima 2, 10) were also created for analysis (again two for each, one based on the quantiles method and one based on the 'min-max' method). These six Negative Experience Scores are also shared here.
Files and variables
File: Mason_et_al._2025_with_anonymized_cage_and_no_Monkey_ID.xlsx
Each row is one monkey.
Abbreviations:
DV = dependent variable in main analysis
IV = independent variable in main analysis
Random = Set as random intercept in main analysis
ARB - abnormal repetitive behaviour
Neg Exp = Negative Experience
min-max = a score per challenge on a 0-1 scale, created by dividing a subject's scores by the dataset's greatest value for that challenge
quants = a score per challenge on a 0-1 scale based on a 'quantiles' method scored each subjects categorically by ranks (typically quartiles)
loc = location
current = current (i.e. status during period of data collection)
Column headings:
Count of Scans: Number of observation scans in total
DV Rock+: Rock+ = rocking, swinging etc. cluster of ARBs (number of observations present)
DV Pace: Pacing and headswinging cluster of ARBs (number of observations present)
DV hairplucking: Plucking self (number of observations present)
DV Motor ARB (Pace + Rock+): This column combines the rocking group and the pacing group to form a pragmatic 'motor ARB' group (number of observations present)
DV ARB Pooled: This group combines all ARBs observed (including rare forms not captured by the original main three categories
IV CURR NEG EXP SCORE (quant-based): Sums scores for current cage location and degree of single housing, using quantiles-based categories
IV PAST NEG EXP SCORE (quant-based): Sums scores for all 10 items of past negative experience, using quantiles-based categories
IV LIFE NEG EXP SCORE (quant-based): Sums all 12 scores for all 12 challenges, using quantiles-based categories
IV CURRENT NEG EXP SCORE (min-max): Sums min-max-based scores for current cage location and degree of single housing
IV PAST NEG EXP SCORE (min-max): Sums min-max-based scores for all 10 past challenges
IV LIFE NEG EXP SCORE (min-max): Sums all 12 min-max-based scores for all 12 challenges
IVAge in yrs: Monkey age in years
IVSex: Sex where F = female, M = male
IVCentre: Centre (facility) - anonymized
Cage (random): Cage ID - anonymized
Room (random): Room ID - anonymized
The following items are the 12 challenges used to create composite Negative Experience Scores, each on a 0-1 scale (where 0 is best for welfare, while 1 is worst):
Cage loc score (min-max): Score for physical location of cage (distance from door + top or bottom row in room), created using min-max scale
Cage loc score (quants): Score for physical location of cage (distance from door + top or bottom row in room), created using category-based (e.g. quantile-based) scores
Curr % obv. Single-caged: Proportion of scans spent single-caged (grate-separations from cagemates scored as 50% as severe as full separation from neighbours)
Curr social as categories: Time currently spent single-caged using category-based scores
Time single-caged (min-max): Total time spent single-caged over life, on a min-max scale
Time single-caged (quants): Total time spent single-caged over life, scored by quantile
Time in hospital (min-max) : Total time spent in hospital over life, on a min-max scale)
Time in hospital (quants): Total time spent in hospital over life, scored by quantile
Pair separations (min-max): Number of times separated from a cagemate over life, on a min-max scale
Pair separations (quants): Number of times separated from a cagemate over life, scored by quantile
Number of projects (min-max): Number of research projects involved in over life, on a min-max scale
Number of projects (quants): Number of research projects involved in over life, scored by quantile
Negative health events (min-max): Number of adverse heath events (e.g. vet treatments, invasive research procedures) over life, scored by quantile
Negative health events (quants): Number of adverse heath events (e.g. vet treatments, invasive research procedures) over life, on a min-max scale
Unsuccessful pairings (min-max): Number of incompatible (aggressive) cagemates over life, on a min-max scale
Unsuccessful pairings (categories): Number of incompatible (aggressive) cagemates over life, using category-based scores
Location moves (min-max): Number of cage moves over life, on a min-max scale
Location moves (quants): Number of cage moves over life, scored by quantile
Time spent indoors (min-max): Total time spent indoors over life, on a min-max scale
Time spent indoors (quants): Total time spent indoors over life, scored by quantile
Rearing enclosure score: Size and location of enclosure in infancy, as a category-based score
Time with mother score: Age at which separated from mother, as a category-based score
Code/software
Excel
Access information
Other publicly accessible locations of the data:
- None
Data was derived from the following sources:
- Private records of two US National Primate Centres
Subjects were 240 indoor-housed rhesus macaques at the California and Oregon National Primate Research Centers (anonymized in dataset): all the residents of 5 rooms per centre. They lived in metal cages, some singly, some in double-size cages in pairs. Behavioural data were remotely collected via live-streaming cameras, in scans repeated every c. 5 minutes for 3-4 hours daily over 4 (ONPRC) or 5 (CNPRC) consecutive days. Pacing, ‘rocking+’ and a third previously validated ARB sub-category, hair-plucking, were recorded in both facilities; present in >5% subjects; and also performed with good internal reliability. After initial analysis attempts, however, pacing and rocking+ were combined as 'motor ARB' (shared here). After results for hair-plucking and motor ARB emerged, all recorded ARBs were also pooled for further analysis: Pooled ARB is also shared here.
Data on negative experiences over the lifespan: we identified 12 types of challenge (either events or facility practices) likely to induce negative affect. Two pertained to current housing: an adverse cage location (low, near the door); and being singly-caged. Ten (extracted from facility records) pertained to past experiences: maternal loss in infancy; being born and raised indoors; living indoors; spending time singly-caged; being relocated; being aggressed by a cagemate; losing a cagemate; involvement in research projects; health events (including research procedures); and spending time in hospital. To capture variation in aversiveness, every monkey was scored (blind to their behavioural data) between 0 and 1 for each challenge. For robustness, for 10 of the items we used two methods that varied in how differential experiences were weighted: a 'min-max' method divided a subject's scores by the dataset's greatest value for that challenge; and a 'quantiles' method scored each subjects categorically by ranks (typically quartiles) for each challenge. The two items pertaining to infancy (age when separated from mother; type of indoor/outdoor reading facility) were always scored 0-1 based on categories. All 22 scores are shared here. (Raw values are not shared for reasons of confidentiality). These scores were totalled to create two Lifetime Negative Experience Scores (maximum 12). Current Negative Experience and Past Negative Experience Scores (respective maxima 2, 10) were also created for analysis (again two for each, one based on quantiles method and one based on the 'min-max' method). These six Negative Experience Scores are also shared here.