There are so many directions and ideas on this subject, but let's start here with this brutally honest fact:

If you want to get the best out of your horse, they need to be happy.

A happy horse will be a horse more willing to learn, more willing to put effort in, more willing to trust you, more willing to give their all, more willing to try new things, more willing to be confident in themselves.

Also, putting aside it's training/riding implications, making sure your horse is as happy as they can be is just the moral thing to do.

Unfortunately, far too often I see riders treating their horses like machines. They treat the horses not much different from an ATV or dirt bike. Get it out when you want to go for a ride, fire it up and speed off. Bring it back and throw it back in the garage when you're done. And I won't say they are necessarily doing this on purpose. For most people, it is unintentional because of a mix of not thinking/considering it, and not even knowing or being exposed to a better way. 

But horses, as with humans, have a greater range of needs and desires in order to be happy. The dirt bike/ATV doesn't have any need for happiness. 

I've included the short video at the top of the post as a reminder that "drilling" the same thing day in and day out definitely does not increase their happiness. Horses, like humans, like different experiences. They like not having a monotonous lifestyle. So make sure to switch up what you do with your horse. Aside from the fact that I am an eventer and like that I have 3 different disciplines to train for, I also like taking my horses out at least once, if not twice, a week for a long trail walk. Sometimes some trotting and cantering. It switches things up and almost about every horse will enjoy it. (Some may take a while to develop the confidence to be on trail and/or alone, but after a while they will get comfortable with it).

Anyway, moving on, Maslow's Hierarchy of Needs is something that I was exposed to years and years ago, outside of horses. But it has almost perfect replication to a horse's needs as well. 

The only difference is that you could possibly argue that horse's would never need/get to the very top rung of "Self-Actualization", although personally I'd err on the side that they do, at least in some aspect.

See the picture in this blog post for the full Hierarchy of Needs, but in a nutshell, the needs are arranged in a pyramid. Needs are built from bottom/base need. And you cannot get to another level without having the previous need fulfilled.

So for example, Physiological needs are the first and foundational need. These involve basic needs/functions such as breathing, food, water, shelter, etc. If you think about the hierarchy in your personal life, you would not be able to focus on any other goals or aspirations if you were unable to fulfill your hunger or thirst. So these needs need to be met before you can move to a higher tier.

Safety and Security is next (health, employment, property, family and social ability).

Love and Belonging is after that (friendship, family, intimacy, sense of connection).

Then Self-Esteem (confidence, achievement, respect of others, the need to be a unique individual).

And finally the top tier is Self-Actualization which encompasses morality, creativity, spontaneity (or to make a horse pun - sponta-neigh-ity), acceptance, experience purpose, meaning, and inner potential.

Again, you need the preceding tier before you can move on to trying to fulfil the following tier. You cannot truly be comfortable in experiencing a sense of friendship and connection if you are struggling to find a place to sleep at night.

I believe horses are the same way. And we can turn this into a little bit of a focus on how these tiers can gauge their happiness. If a horse does not have their physiological needs met, if they don't have access to the food they need, they will not be very secure or open to other things. 

If they don't feel social connection and security in their surroundings, they won't be able to be confident in themselves.

And I would argue that horses are capable of reaching the Self-Actualization tier, I would say that there are horses that experience purpose and meaning in life. Not many, but these are the horses you see whose eyes light up and they get a bounce in their step and maybe that "Look of Eagles" at the prospect of whatever they truly enjoy in life. 

These are the horses you see that truly enjoy their job. The ones standing at their stall door or pasture gate ready for you to bring them in to ride them. The ones with the gleam in their eye when they enter the arena, or maybe when you point them at a jump. 

Many horses may not get to that point, either from their personality or that they never find what truly excites them (beyond eating). But at the end of the day, we as riders and owners need to make it our goal to get our horses as high up that Hierarchy of Needs as we possibly can. Because the higher up the horse is, the more happy they will be, the more confident they will be in themselves, and they will be more confident and trusting in you. And that is one of the biggest items: confidence. A confident horse will be a trainable horse, will be a successful horse, and will be a pleasure to ride.