Neural modulators of temperament: A multivariate approach to personality trait identification in the horse.

The research investigates the connection between dopamine and temperament in horses, utilizing multiple methods including a questionnaire, direct observation, Spontaneous Blink Rate (SBR) and Behavioral Initiation Rate (BIR). The findings indicate a significant relationship between these aspects, which could be helpful for early identification of certain conditions related to dopamine dysfunction in horses.

Research Methodology

• The researchers used a multivariate and mixed methods approach, employing both behaviour observation and quantitative measures.
• A group of 99 horses were studied. Their temperament was gauged via a questionnaire and direct observation.
• Two indirect measures of dopamine activity were recorded: Spontaneous Blink Rate (SBR) and Behavioral Initiation Rate (BIR).
• The study employed an analysis method called Principal Component Analysis (PCA) to summarise the large set of 36 different temperament variables into a manageable set of nine broad, overarching factors (principal components).

Main Findings

• The nine principal components identified accounted for 72.4% of the total variance. These included factors such as ‘Anxiety’ and ‘Docility’.
• Correlation analysis between these principal components and markers of dopaminergic activity (SBR and BIR) was carried out using the Spearman rank correlation coefficient method.
• Results revealed a significant positive relationship between the ‘Anxiety’ component and SBR. This means that horses showing signs of anxiety blinked more frequently.
• On the other hand, ‘Docility’ was found to have a significant negative correlation with SBR, meaning docile horses blinked less often.

Implications and Future Research

• These findings suggest a link between dopamine (as indirectly measured through SBR and BIR) and temperament in horses.
• The study presents potential mechanisms relating to how the dopaminergic and GABAergic nervous systems could be involved in these observed effects.
• This research suggests that temperamental changes could potentially be used to identify horses at risk of dopaminergic dysfunction.
• However, further research is needed to expand on these findings and fully understand the implications and applications of this potential relationship.