Research Reference:

Lundberg Paulina, Hartmann Elke, Roth Lina S.V. (2020). Does training style affect the human-horse relationship? Asking the horse in a separation–reunion experiment with the owner and a stranger. Applied Animal Behaviour Science, Volume 233, December.

Link to Research Paper: 

https://www.sciencedirect.com/science/article/pii/S016815912030232X?via%3Dihub

Link to Daily Mail Article:

https://www.dailymail.co.uk/sciencetech/article-8909547/Horses-DONT-form-attachment-bonds-owners-study-finds.html