The researchers conducted the survey of 4,000 adults in an attempt to answer the question of how many Americans own a firearm — and why — amid a lack of overall data and statistics on gun ownership. They found a broad regional variation in gun ownership — from as low as near 5% in some areas to as much as 66% in others. In individual states, this ranged from 5.2% ownership in Delaware to 61.7% in Alaska.

The researchers discovered the variation was due to everything from local and state firearm laws to cultural and social norms. Those who reported the prevalence of a "social gun culture," in fact, were 2.25 times more likely to own a gun.

"In many parts of the country, these social norms include participation in social activities around gun ownership. These social gun cultures have rarely been formally studied but may be important determinants of gun ownership," the study's authors wrote.