No, we are actually hardwired to be negative, because it's directly intertwined with our fight or flight response.
Positive emotions are only a result of the successful completion of surviving (be it surviving an encounter, drinking or eating [necessary actions to stay alive]). Happiness/love/etc are useless unless you are alive, therefore fear/anxiety/panic are the most basic mental functioning and are first in cognitive processing.
You brain is hardwired to negatively assess everything, as it's constantly looking for danger to keep itself alive.