A CBS News Poll in 2008 asked the following question:
"Which would you prefer to be stranded on a deserted island with—another human being or a dog?"
74% chose a human, 22% a dog, 1% said neither, and 3% didn't know. It was only 1%, but the people who said "neither" worry me.
Back in 1958, the Gallup Poll had a different desert island question:
"Of course it would depend on the person, but other things being equal, would you rather be cast up on an island alone with a Democrat or a Republican?"
27% chose a Democrat, 14% a Republican, 34% neither, and 34% no opinion.
I assume that "neither" here means they'd prefer someone who wasn't a member of either party, not that they'd rather be alone.
The obvious explanation for the Democratic edge is that some people would rather have someone who shared their political views, and that there were more Democrats than Republicans at the time. That's certainly part of it, but it doesn't seem to explain the magnitude of the Democratic edge. In the same survey, 50% said that they were Democrats and 31% said Republicans. That's a considerable lead for the Democrats, but less than the almost 2:1 edge in preference for a companion on the island.
By the way, I found these questions in the iPOLL database maintained by the Roper Center for Public Opinion Research at the University of Connecticut. It's an essential resource for research on public opinion, and unless otherwise indicated, is the source of all survey data mentioned in this blog.