Personality

Personality

1. Definition; What is personality; individuals (from a same species) differ from each other in their behaviour). This variation is temporally consistent. These behavioural tendencies general across contexts (to some extent), they are heritable, they can have fitness consequences.

2. History- historically, individual differences in behaviour viewed as noise; non-adaptive and random. Later realisation that such variation could be advantageous; produce (contained) variability, selective advantage? if not all individuals react the some way, then chances are that some will survive under certain conditions.

3. Why study personality- Understadning a species and the strategies animals empty to survive and reproduce; important for comparative approach to better understand humans. Carry out studies that cannot be done with humans (greater control over the environment, genetics etc), Practical implications; animal-human interactions, animal welfare, animal conservation.

4. How to measure it? The psychologists view; self rating (questionnaires), assessment by knowledgeable informants (e.g. peers, parents, teachers etc). Overall score, scales, and comparison with human personality theories. Anthropomorphism; the attribution of human characteristics or behaviour to a god, animal, or object. The biologists way; observation (e.g. which behaviours, consistency of behaviour), Experimentation (e.g. novel object, novel environment, assessment by knowledge informations (e.g. observers, keepers etc).

5. How to measure it? the level of analysis; Population specific personality traits; Specific to a species, cannot be compared across species. Universal personality traits; consistent variation across species, can be compared e.g. shyness-boldness continual; aggressiveness; exists in different species. Important; species biology strongly determines their behaviour, comparing behavioural traits across species may not be appropriate, e.g. lions and antelopes; an escape response is easily trigger in antelopes compared to lions, does it mean that antelopes are shy and lions are bold.

6. The levels of analysis; e.g. lions and antelopes, the antelopes behaviour (and the lions) are the result of ecological pressures leading to species-specific behaviour (antelopes are frequently attacked by predators and their survival depends partly on their ability to run away as soon as possible). Personality traits are 'real' if; between individual variation > within- individual variation.

7. diagnostic criteria- validity; correspondence between ratings and observed behaviour, knowledge of the species behaviour, confounding factors, independent observers (naive), ecological validity. e.g. mouse lemur; boldness and exploratory tendencies, measures in the novelty task does not correlate with measure in the more ecologically valid feeding test.

8. Diagnostic criteria- Reliability; correspondence between raters/ observers; multiple observer/raters are tested for reliability, do they see/think the same thing? Usually problem with items that do not have a clear association with behaviour e.g. eccentric, jealous vs dominant, aggressive. Standard procedure in observational research; intra or inter-observer reliability. Often missing in animal personality research.

9. How to measure it? how would you assess personality in macaques? playback of dog barks (predator) and measure reaction (boldness). Present novel object and measure reaction (neophobia). Behavioural observation of association with other individual (connectedness/ sociability).

10. How to measure it? Why would you want to assess personality in macaques? Personality can be good predictor of survival in the wild (brewer-Harrison et al 2004). Foxes assessed as 'bold' (via experiments and ratings) were not good candidates for re-introduction; lower survival rate, higher probability of leaving the release site (and therefore settling in more hostile habitat).

11. Anti predator behaviour, Hawk & chaffinches (Quinn & Cresswell, 2015); measure baseline activity levels under same conditions; some chaffinch are more active than others; hyperactive and hypoactive behavioural types (personality), does the personality of chaffinches influence their response to predator? if so, are some personalities favoured under certain conditions. experiment; conditions- higher risk alone, high risk with non-target, low risk alone, low risk with target. High risk alone and high risk with non-target= escape. Low risk alone and low risk with target= freeze. Results; correlation between level of activity and anti-predator persons- Hypoactive; more likely to freeze when low risk, less likely to escape when high risk. Hyperactive; less likely to freeze when low risk, more likely to escape when high risk. Hypoactive; favoured under low predation pressure. Hyperactive; favoured under high predation pressure.

12. Reproductive success, Bighorn sheep (Reale et al 2000); measured personality as the likelihood to approach a salt lick associated with capture traps, and the time spent in proximity of the salt lick; bold individuals approach more and stay longer. Measured time at 1st reproduction (primiparity) and weaning success. Bold males reproduce earlier and have a higher weaning success than shy ones, Bold males more willing to access to valuable resources (more time feeding and better food).

13. the importance of pre- and early post-natal experience; prenatal stress i pregnant rhesus macaques induced impaired neuromotor development and attention deficit at birth. Negative effects persisted over time (less active, socially engaged); inhibited personality. Adult rhesus reared with minimal social experience show little social interest and competence towards other macaques; low extraversion, low agreeableness, low conscientiousness, low opennses, high neuroticism.

14. Genes x Environment interactions; neurotransmitter serotonin there are variations in the genes involved in the functioning of serotonin; in humans, short allele associated with neuroticism and lower resilient to dress. Rhesus Macaques (Shannon et al 1998); Nursery raised or raised by mother (environment), Characterisation of the genes involved in the functioning of serotonin (genes). Nurses raised have better visual orientation skills and attention, Short allele associated with lower visual orientation and attention but only in nursery raised infant, not mother raised. Later nursery raised with short allele also showed higher rates of aggressive behaviour.

15. Personality and health; sociability and simian innunodeficiency virus (SIV, equivalent to human HIV); individuals scoring high on sociability showed greater decline in the viral load (stronger predictor of survival). Baboons 3 personality types.

16. Training of animals; reduces stress during husbandry procedure (e.g. health check) or research protocols (e.g. blood sample for hormone analysis, touchscreen); assess personality (novel object) to determine which individuals are most suitable for training .

17. Well-being of animals used in research; animals that display an inhibited personality show deficiencies in social abilities and general adaptability.

18. Domestic cats (Natoli et al 2005); behavioural observations of 3 groups of feral cats; recorded aggressive, submissive, affiliative, territorial, display and mating behaviour. Some cats are more proactive (lots of aggression, territorial and reproductive behaviour), other are more reactive (more submission display...). Proactive cats have higher reproductive success (sire more offspring). Proactive cats also have higher probability of being infected by the feline HIV (lethal).

19. Giant Pandas (Powell et al 2008); introduction of novel objects and questionnaires to keepers,vets and trainers. Personality of gains pandas correlates with socio-sexual performances (shy individuals have poorer performances than bold ones). Important implications for breeding and conversation programmes.

20. Survival in the Wild, swift foxes (Bremmer- Harrison et al 2004); animals assessed as 'bold' (via presentation of novel objects/people and ratings) were not good candidates for reintroduction; lower survival rate, higher portability of learning the release site (and therefore settling in more hostile habitat)

21. Extreme cases; invasion of introduced species (Chapple et al 2012); does the personality of individuals introduced affect the success of their introduction.

22. Summary; persoanilty in animals exists and can be objectively measure. Variation in animal personality provides a substrate for natural selection to act on. Learning about personality in animals in important for our general knowledge but also to better understand personality in humans and how it affects our health.