Not all vices are created equally.

New research published in Human Brain Mapping shows that pornographic images trigger the reward centers of the brain more than the prospect of money or gaming in healthy adult men.

The study explored how the human brain becomes conditioned to receive internet-related stimuli, particularly pornography, gambling and video gaming — some of the most common internet-based addictions — as a reward, even in a healthy and non-pathological context.

The experiments involved 31 male participants aged 19 to 38 years, all healthy and right-handed, to control for sex differences in reward processing. Each participant was then asked to choose their preferred stimuli: pornographic images, video game screenshots and pictures of money that came with a 50 cent bank increase. This personalization factor ensured the stimuli were genuinely rewarding to each participant.

Another angle research investigated how the brain responds to neutral stimuli when associated with rewarding outcomes. To do this, each rewarding image was also paired with a geometric shape amid a lineup, while a fourth shape was paired with no reward at all.

Researchers collected data from MRI scans, skin conductivity tests — which measure physiological arousal — and subjective ratings from participants.

In all trials, the geometric shapes associated with one of the three rewarding images were rated as more pleasant and arousing than the unrewarding shape — with pornographic images coming out at the top of the heap. Notably, these shapes associated with porn jumpstarted the brain’s reward processing pathways quicker than gaming and money.

The findings suggest that porn — and, presumably by extension, sex — feels more rewarding than gaming or money, and thus may be considered more addictive than gaming addiction or gambling. Previous research agrees with the results, showing pornography is more arousing and effective than some other addictive activities.

By understanding the neural mechanisms behind reward processing in the brain, such research is key to discovering and developing new therapies for the treatment of addiction.