It's give and take between the two, as the traits someone is born with can strongly influence what sort of nurture they know. Nurture is the encrypted data they carry while Nature is the codex for deciphering and understanding it.
Using myself as an example, my nature has me get a happy response from pain. My nurture used to reel in horror at the notion, but overtime it adapted into something more comfortable once I recognized it as a good thing instead of something creepy. If I hadn't had the trait to appreciate pain improperly, that path of nurture would have never occurred.
"But if you look at it, he/she wasn't born to hate or fear dogs."
The capacity to feel fear to what escalations they are capable however is strongly predisposed by Nature. Someone fearless or more capable of overcoming fears can get around it.
There's also some forms of fear that exist prior to personal experience. If someone's deathly afraid of snakes, is it only because of those around them influencing them/a bad interaction with them, or aspects of nature paving the way for them to respond like that such as a fear of the unknown, a fear of underfoot threats, a fear of unfamiliar motion, etc?
TLDR: Nature influences how Nurture is taken.
I believe in Nurture, mainly from personal experience. To back up my statement Ill give an example. Lets say a 5 year old gets bitten by a dog. You can say many years after that he/she may have some negative feeling against dogs (fear, hatred, etc.). But if you look at it, he/she wasn't born to hate or fear dogs.
Depends on the extent of both.
I believe nurture is the strongest of the two if given more time to manifest then nature, but nature itself is resilient and when repressed has a way of resurfacing in other eruptive ways. I know I've had my own problems with shedding some destructive behaviors that stemmed from how I was raised. I know no matter how much I condition and coach myself these behaviors will still be around for the remainder of my life. In that sense, nature is stronger. Again, it's just the extent of one over the other.
You can take the tiger out of the jungle...
In your personal experience were you treated poorly by your own parents or by non-relative outsiders?
If the answer is by your parent, then the question is not that simple because you inherited your genes from your parent who was more likely to act according to his/her own genes, so there is a confounder of what came first the EGG or the CHICKEN? Of course, we also have to look at the Chicken grandparents and other relatives Rooster sings cock-a-doodle-doo
If the harm was done by a non-relative outsider, then in your case is easier to say that it was nurture, maybe still somewhat genetically predisposed, but mostly about nature.
We would need a big long study to sort this Chicken or Egg thing, the $$ million dollar question is for you, would you join a study to find out?