Jeff Hancock is a professor at Stanford University, where he studies deception and technology. The views expressed here are his own (and contain some graphic language).

Donald Trump and Hillary Clinton are seen as equally trustworthy by the public, and yet Trump makes false statements almost four times as often than Clinton.

How is this possible?

I study deception and trust and am frequently asked this question, given that fact checkers rate Trump's statements as entirely false 52% of the time compared to Clinton's 12%.

There are several possible explanations. One is that we like and trust people who look like we do, an effect known as homophily. This also allows us to discount or ignore things that we might otherwise not. That could explain why so many white men support Trump despite his persistent falsehoods.

The two candidates also have distinctly different communication styles. Trump speaks in a direct manner, with simple words and sentences, a style that comes across as authentic and trustworthy. Clinton speaks more cautiously, qualifying her statements and using more complex sentences, a style that leads people to believe she is hiding something even when she isn't.

But neither of these explanations fully account for why Trump's more frequent lies don't affect his trustworthiness more. One explanation is that this isn't really about lying, but about bullshit. In his book On Bullshit, Harry Frankfurt distinguished between the two by noting that to lie, one has to purposely hide the truth from others.

A bullshit artist isn't concerned with the truth, but instead makes things up to suit his purpose. He doesn't care if the things he says describe reality accurately. When the fisherman says that the fish was this big, with his hands wide apart, the actual size of the fish isn't what's important, it's the entertainment of the listeners.

Related: Why Clinton and Trump need to lie

The idea that Trump's false statements are bullshit can help explain why his supporters don't care that fact checkers say he's lying.

For example, Trump has said that he'll build a wall across America and make Mexico pay. If that's bullshit, Trump doesn't need to care about the feasibility or what the true cost might be -- and neither do his supporters. What's important is the message of stopping illegal immigration. Or when Trump makes false claims about the trade deficit or the unemployment rate, the reality is less important than his supporters' sense that the economy is leaving them behind. When Trump says that crime is up and you'll get shot walking in urban centers, the reality is less important than his message of law and order.

Frankfurt emphasizes that people bullshit when they speak about topics that they are not well-versed in or when the facts don't line up with the overall message. Trump has been upfront about his outsider status and his lack of debate prep and knowledge on government policy. The fact that he responds to complex topics with bullshit is perhaps not surprising.

This argument maps nicely onto a recent piece in The Atlantic about Trump and his supporters versus the media: The press takes him literally, but not seriously; his supporters take him seriously, but not literally.

But this is not an argument to explain away the seriousness of Trump's false statements. On the contrary. The bullshit artist may or may not know the truth but doesn't care about it either way. As Frankfurt writes, "bullshit is a greater enemy of truth than lies are." At least with a liar, you can present evidence to the contrary. The bullshitter doesn't care about facts.

Now, as the debate around Trump's 2005 comments about groping women swirls, this issue is extremely important. If he is perceived as a bullshitter, engaging in harmless "locker room" banter, will the voters forgive his statements? The fact that many of his supporters are still on board seems to support this, but there are limits to how much voters are willing to put up with. Trump's standing in the polls has taken a nosedive.

And here's an amazing coincidence. A recent book cataloged all the synonyms for bullshit, and one of the oldest dates back to the 1400s. It originally referred to trickery and scamming, although its meaning has evolved to include general nonsense and insignificance. That word: trumpery.