Psychologists say horses use a combination of facial expressions and voice tones to work out how people are feeling - and they can even do it with complete strangers. The study could help us develop a better relationship with the species, which humans have depended on for more than 5,500 years. According to the researchers, horses could even catch-up to dogs in terms of human emotional intelligence, if changes to training are made in response to the latest findings. It has been suggested that recognition of social signals such as emotions play an important role in how horses live and interact with humans. Unlike dogs, few studies have investigated horses' awareness of human emotions.