Lowe "has this incredible way of making you feel like you're the only person in the room," Harrison said in a recent interview. "That's a great quality, and the thing is, it's sincere.
"It's not an act with him, and what really makes the difference is his sincerity. His charm and his charisma makes these women feel like, 'This is it, like we could literally stop this date and go get married.' I don't think I've ever seen a season where so many relationships are so sincere and serious and that could only lead to one thing: a very combustible situation."
Lowe, who is from Dallas, tried to win Emily Maynard's heart last season on "The Bachelorette."
He ended up in third place, and although he didn't walk away with the girl, he did leave with a friendship with finalists Arie Luyendyk Jr. and Jef Holm. Luyendyk appeared on the first episode of "The Bachelor" to give Lowe support.
Harrison says that while male contestants tend to bond, women tend to bicker and conspire against one another.
"The way they are manipulative and they fight, and they try to win — that's them," he said. "And when you shine a light on it maybe it's not so pretty, but that happens in every bar and church and library in America when people are getting together and it's just exploited to the nth degree on 'The Bachelor.'"
But, he adds: "It's an extraordinary situation, too. I mean, I'm gonna come to their defense a little bit. They're all dating the same guy. But ... the guys seem to have this ... camaraderie, and we're pretty simple animals. ... I think women are much too, way too dynamic and smart for this game, where guys are like, 'Whatever, OK.' So I think it's geared easier for men than for women, who I think are just way too much of too many personalities piled into one house."
Harrison said he's learned that people end up showing their true colors on reality television.
"One thing about this show that I find incredibly compelling ... is you can't save people from themselves ultimately. Their personalities will shine through."