What effect did the advent of agriculture have on the level of interpersonal violence seen in the archaeological record?

Determination of the territory.

Explanation:

Territory is an extension of the land that belongs to a certain group of people. In the matter of organization, it was important so nobody enter somebody's else territory, unleashing confrontations.

We don't have enough evidence to prove how the hunter-gatherer groups delimited their territory given that their livehood was based in the animals they hunted or fished and the vegetables, fruits and seeds they collected. This implied a constat migration and there was no need to limit the territory because they took turns inhabiting different places.

When the groups started to settle down, they domesticated the plants and the advent of agriculture began. In order to do this, they have to live for extended periods of time in the same place and get to know it; and depending on how big the group was, they needed more or less extension of land.

While there were groups that secured their food through the agriculture, there were also groups that hunted and gathered, and when they couldn't access to food, they would stold from the first group. This triggered many violent encounters, with the consequence of the delimitation of the territory. They would do this by building walls and fences or even surrounding the lands where they harvested, with the houses they lived in. They would also organize militarily to fight back when they wanted to steal the crops. In this way, the different groups would recognized another's territory.

We can deduce this from the archaeological record because we found:

rests of the walls and fences, arrowheads and other weapons from the encounters rests of the plants and seed they used burned ceilings (may indicate an outside attack)