For better or worse, most scientific journals still operate on a business model dependent on physical subscriptions. Since this sets something of a limit on how much can be published, and since scientists tend to prefer paying for positive results vs negative, there has been a strong cultural bias toward favoring positive results.
The good news is that this is gradually changing. As scientists begin to understand that online distribution models don't have the same sorts of limitations, and that search can be a powerful tool, there has been a move toward at least collecting negative results. Of course, they still don't benefit the scientists in the "publish-or-perish" world, but even that may be changing...maybe...
The good news is that this is gradually changing. As scientists begin to understand that online distribution models don't have the same sorts of limitations, and that search can be a powerful tool, there has been a move toward at least collecting negative results. Of course, they still don't benefit the scientists in the "publish-or-perish" world, but even that may be changing...maybe...