Making a big decision is never and easy thing to do. Just ask Vice President Joe Biden or Rep. Paul Ryan (R-Wis.), both of whom are trying to make big choices about their political futures. Biden's been at it for months, Ryan since last week.
But why do some people seem to go with their gut and others take forever?
Researchers say science can help explain the process behind our decision-making, and when we reach the "decision threshold" then pull that mental trigger.
Roozbeh Kiani is a neurobiologist at New York University whose lab studies the decision-making process and how commitments to choices are made.
Kiani says that making an optimal decision is based on choosing the right pieces of information, then combining it with our past experiences, our senses and the expectation of a reward.
For Biden, he has to weigh the fact that he's failed on two previous campaigns for president (1988 and 2008), while collecting information about the current field of Democratic candidates.
"If you are making a decision based on weak evidence, the decision will take longer to make," Kiani said. "If the source of information is not clear, say that Biden wants to run, but he's not sure whether he has a chance, then he does not have enough signal to work with. He will require a lot of time to gather evidence and commit to a choice."
According to news reports, Biden has been weighing a bid for the Democratic nomination for president for at least several months. The process was confounded by the death of his son Beau in August.
Some sources close to Biden said he would decide by the end of summer, now it's become November.
Another possibility is that people need different levels of what's known as satisfactory evidence before they're ready to make a call.
"I may be able to make a decision with two units of evidence," Kiani said. "It may take you five units of evidence."
A third possibility, according to Kiania, is that the environment and the data are shifting.
"He's worried about the volatility of the political landscape, and he's waiting to see what his rivals are going to do," he said.
Biden's long process could indicate he has a fear of closure, according to Arie Kruglanski, professor of psychology at the University of Maryland. In this way of thinking, there are two kinds of people, decisive and thoughtful, who are driven by both fear or the need to finish a mental calculation.
"The need for closure leads to decisiveness," Kruglanski said. "These are people that for whatever bit of information is available, they reach a decision on that basis without researching it further. On the other end are people who do not need to decide quickly, Sometimes they have a difficulty reaching closure, because closure could be committing an erroneous decision."
And what about that feeling you get, waking up and knowing exactly what to do? That occurs when our brain has been subconsciously processing lots of information about the right choice and reaches the threshold while resting.
Taking a long time to decide on a complex issue with high stakes -- such as whether to take an new job, get married or run for president -- isn't the same as deciding on what to eat for dinner, the experts said. For that reason, it's not clear that the process for one decision reveals that much about your personality.
"For some decisions you want to be very accurate," Kiani said. "For some other decisions you want to be fast. Being fast usually comes at the expense of accuracy."