fillies more nervous, submissive than colts

Question
hello sir. hope you can clear my doubt:

may i know why fillies are nervous than colts?

at the same time, why they are more submissive than colts?

would you advise to buy a filly or mare rather than a colt, gelding or a stallion for few buyers?

Answer
In my experience, I have found no difference in fillies and colts in nervousness or submissiveness. If the young horse is trained correctly they will all be well behaved and respectful horses.
Which brings me to the last part of your question. I advise to buy what ever horse fits the task that you wish it to do. I don't buy a horse based on "mare or gelding". Again, if the horse has had proper training, they will all be productive citizens in the equine community. I advise very few buyers to purchase a stallion. There are special considerations to owning a stallion. The first of which, stallions are usually needed only for breeding purposes. Unless you are in the breeding business, you do not need one. You will need a special place to put your stallion away from the other horses. AND....unless that stallion has had extensive professional training, it can be very dangerous to handle. They do not think like a mare or a gelding and can become extremely aggressive.