DOI: 10.5061/dryad.6hdr7sr7c
title: Short and long-term effects of endogenous cortisol on personality traits and behavioral syndromes

description: Animals express consistent individual differences in some behaviours,
 termed animal personality but behaviours can also considerably vary within
 individuals, within minutes or hours, due to environmental stimuli.
 Consistent among-individual variation is often assumed to be mediated by
 hormonal mechanisms. Hormones are also involved in flexible and fast
 responses towards environmental stimuli. Even though basic mechanisms by
 which hormones regulate behaviours are known, much of the quantitative
 patterns underlying hormone-behaviour interactions within and among
 individuals, remain unclear. Here, we conducted two experiments to
 investigate the immediate, short-term effects of experimentally elevated
 cortisol titres on well-known animal personality traits (Experiment 1) and
 the potential long-term effects of such experimentally elevated cortisol
 titres (Experiment 2) in the medium-sized cavy (Cavia aperea). Therefore,
 we tested how personality traits related to stress-coping, novelty seeking
 and social behaviour react within hours towards elevated cortisol. In
 Experiment 2, we tested if a three-weeks elevation of cortisol affects the
 same personality traits after cessation of the hormone treatment. We
 investigated effects on the mean levels of behaviours, i.e., the
 personality type, the temporal consistency, i.e., repeatability and
 among-individual correlations of traits. In experiment 1, we found
 cortisol to lead to more aggressive behaviour and more passive
 stress-coping while other traits were unaffected. In experiment 2, we
 found no long-term persisting effects. Both measured hormones, cortisol
 and testosterone, showed correlations to several personality traits, these
 correlations were, however, unaffected by the cortisol treatment. Animals
 receiving the cortisol treatment showed higher repeatability, for one
 stress-coping trait and lower repeatability for testosterone
 concentration. Interestingly, sexes differed only in few mean trait
 expressions but showed different correlation structures across traits.
 Taken together, our data indicate that personality traits in adult
 individuals are very consistent and only react via short-term fluctuations
 towards internal hormonal signals.
description: These are the accompanying raw data to the publication: Short and
 long-term effects of endogenous cortisol on personality traits and
 behavioral syndromes. Detailed methods can be found in
 the article. Compiled are raw data of two experiments. Experiment I: Data
 of behavioural observations under control (undisturbed) versus treatment
 (received a single dose of exogenous cortisol).
 Experiment II: data of behavioural observations and blood plasma
 hormone concentrations taken 1 month (Testround 1) and 2 months (Testround
 2) after the end of a three-weeks cortisol feeding experiment. Raw data
 were not processed in any way. 
description: # raw\_data\_Short and long-term effects of endogenous cortisol on
 personality traits and behavioral syndromes
 In total, 14 adult
 unrelated female *Cavia aperea* were used for Experiment I and 50 (24
 males, 26 females) adult animals were used for Experiment II. All animals
 descended from a breeding population of wild cavies kept at Bielefeld
 University, bred and raised under identical laboratory conditions. In both
 experiments, females received 5 mg cortisol powder (Ref. Nr. 352450050;
 Arcos Organics) on a slice of cucumber, while males, which are on average
 slightly heavier than females, received 6 mg. In Exp. I, animals received
 a single dose of cortisol (or a control cucumber) directly followed by a
 behavioural test. In Exp. II, animals received either the cucumber with
 cortisol or the control on two out of three days for a period of 21 days
 and behavioural observations started two weeks after the end of the 21
 days treatment period. ## Description of the data and file structure |
 Experiment 1: | | | | | | :----------------- |
 :---------------------------------------------------------------------------------------------------------- | :- | :- | :- | | ID | animal identity | | | | | Testdate | date the test was conducted | | | | | Treatment | C - control; T - cortisol treatment | | | | | Body mass \[g] | body mass of individual | | | | | E\_time \[s] | latency to escape hand in seconds | | | | | Stimulus-animal | identity of stimulus animal | | | | | Naso-nasal | number of naso-nasal contacts initiated by the focal individual | | | | | Naso-anal | number of naso-anall contacts initiated by the focal individual | | | | | Evade | number of times the focal animal evades contact initiated by the stimulus animal | | | | | Curved Body | number of times the focal animal adopted a curved-body posture | | | | | Chase | number of times the focal individual actively chased the stimulus animal | | | | | Attack | number of times the focal individual attacked the stimulus animal | | | | | Sum\_Aggressive | sum of all aggressive interactions initiated by the focal animal | | | | | sum\_positive | sum of all socio-positive interactions initiated by the focal animal | | | | | Struggle \[s] | time (in seconds) the animal struggled to escape the observer within thirty seconds | | | | | time | video recording in the home enclosure; 1 - two hours after cortisol was fed, 2 -  | | | | | activity \[s] | time (in seconds) the animal was active during the 1 hour recording | | | | | comfort \[s] | Amount of time the animal performed comfort behaviours such as grooming or eating | | | | | nervous \[s] | amount of time the animal performed behaviours indicating nervousness | | | | | | | | | | | | | | | | | Experiment 2: | | | | | | ID | animal identity | | | | | sex | sex of animal | | | | | location | enclosure identity | | | | | mother | maternal identity | | | | | Treat | C - control; T - cortisol treatment | | | | | age\_start\_d | age (in days) of the animal at experimental start | | | | | Mass | body mass in gramm | | | | | Hand | hand-escape latency in seconds | | | | | Struggle | duration of struggle behaviour in seconds | | | | | NO\_latency | latency to touch a novel object  | | | | | NO\_touches | number of touches of novel object | | | | | Socpos | sum of all socio-positive interactions initiated by the focal animal | | | | | Evade | number of times the focal animal evades contact initiated by the stimulus animal | | | | | Aggressive | sum of all aggressive interactions initiated by the focal animal | | | | | Aggression\_binary | whether the focal individual initiated aggressive interactions towards the stimulus animal; 1 - yes; 0 - no | | | | | Stimulus | identity of stimulu animal | | | | | Testround | 1 - first test round, 2 - repeat of all tests after 4 weeks | | | | | Hormon\_ID | number of hormone sample | | | | | Cort\_ng\_ml | plasma cortisol concentration in ng/ml | | | | | Testo\_pg\_ml | plasma testosterone concentration in pg/ml | | | | ## Sharing/Access information ## Code/Software \-