Horses (Equus caballus) select the greater of two quantities in small numerical contrasts.

The research article discusses how horses were able to select the greater quantity of items from two options, especially when the numbers involved were small.

Objective of the Study

• The research aimed to explore the ability of horses to calculate and select the larger of two quantities, a cognitive skill previously studied among human infants and non-human primates.

Design of the Experiment

• The experiment involved 56 horses who were subjected to different numerical contrasts. These contrasts were 2 versus 1, 3 versus 2, and 6 versus 4. Another control contrast for volume, 2 versus 1 large, was also introduced.
• The horses were then tasked with making a choice by pressing their snout against the container holding their chosen numerosity.

Results and Findings

• The study found that horses typically chose the container with the greater number of items. This happened particularly when the numbers involved were small.
• This behavior suggests a spontaneous ability to assess quantity. It was observed even when horses were not trained or incentivized to choose a larger quantity.
• The significance of these results is that it demonstrates a cognitive skill in horses that was previously believed to be present primarily in primates and human infants.
• The results also add to existing evidence demonstrating spontaneous quantity assessment in various species.

Implications of the Study

• This research contributes to the ongoing efforts to understand the cognitive abilities of different animal species, especially in the context of numerosity selection.
• The findings could potentially influence how animals are trained or their cognitive abilities are nurtured.
• The study also highlights the importance of further research on animal cognition involving numerical and volume contrasts.