Not voting and witnessing a crime without acting might have more in common than you think.

The big upset the BC NDP suffered last night, as well as low voter turnout (Elections BC put it at 50 to 52 per cent), could have been caused in some measure by a psychological phenomena known as diffusion of responsibility -- the same behaviour that can occur when large groups of people witness a crime and assume someone else will help the victim.

That's one theory, according to Simon Fraser University psychology adjunct professor Joti Samra. But why would potential voters assume someone else will do it for them? Samra said advance polling may be to blame.

"It's not apathy. People just hope others will act, and that the results will be what they expect. Basically, people felt the outcome was already decided," she said.

If polls had indicated a tight race between the governing party and the New Democrats, would the results have been different?

"Absolutely. If the speculations had been different, more people would have taken action. People had to think that their own voice would have an impact," she added.

Samra said this type of responsibility-shirking is more likely to occur in conditions of anonymity, like elections. It's the bystander effect, she said: the more people present, the less likely people tend to take action.

But while the media may be implicated by representing the results of opinion polls as definitive, she said, the real culprit is the person that stayed at home.

"Potential voters need to recognize that every single voice counts."

Aurora Tejeida is completing a practicum at The Tyee.