Ted Cruz
As he has risen in the polls, more attention is being paid to Texas Sen. Ted Cruz's overall electability as a man who looks, as one fellow Princeton classmate described him: "about as telegenic as an undertaker."

The answer as to why so many people dislike the Texas Republican instinctively is one that intrigued Dr. Richard E. Cytowic, a professor of neurology at George Washington University.

Writing in Psychology Today, Cytowic noted that Cruz's "atypical expressions" left him "uneasy," and that he was not alone among people who have watched Cruz up-close and from afar.

"Note how many colleagues and former associates 'loathe' him. A Bush alumnus told the New York Times' Frank Bruni, 'Why do people take such an instant dislike to Ted Cruz? It just saves time.' Former Senate Majority leader Bob Dole says, 'Nobody likes him,' while Rep. Peter King sees 'malice.'" Cytowic wrote. "According to The Washington Post, screenwriter Craig Mazin, Cruz's former Princeton roommate, has called him a 'huge asshole,' and 'creepy.' He's Tweeted, 'Getting emails blaming me for not smothering Ted Cruz in his sleep in 1988.' The distaste for Cruz even extends beyond the US: Germans say Backpfeifengesicht, meaning a face in need of a good punch."

According to Cytowic, the distaste for Cruz's face starts with his smile.

"As a neurologist it is my business to notice things out of the ordinary and probe them," he wrote. "Senator Cruz's countenance doesn't shift the way I expect typical faces to move. Human faces can't help but broadcast what we feel, what we may be thinking, and even what we may intend."

"I have rarely, if ever, seen a conventional smile from Senator Cruz. In a natural smile the corners of the mouth go up; these muscles we can control voluntarily as well. But muscles circling the eyes are involuntary only; they make the eyes narrow, forming crow's feet at the outside corners," he continued. "No matter the emotional coloring of Senator Cruz's outward rhetoric, his mouth typically tightens into the same straight line. If it deviates from this, the corners of his mouth bend down, not upwards."

"Downturned expressions usually signal disagreeableness or disgust. But I honestly don't know because such an expression is rare in the context of public presentations that are meant to win people over. He may well be unaware that the message of his body language is incongruent with his words," he said before concluding, "Google 'Ted Cruz smiling,' and judge for yourself. For the record I am not a Democrat. I'm at a loss to verbalize what unsettles me so when I watch the freshman senator. But it leaves me cold."