Katherine Heigl doesn't believe in love at first sight.

The 'New Year's Eve' actress - who is married to musician Josh Kelley - thinks strong feelings grow over time but she accepts you can tell if you like someone as soon as you meet.

She said: "I don't believe in love at first sight. I think loves grows as you get to know the person. But definitely I believe in chemistry. You can be attracted to somebody and instantly feel something you've never felt before. I swear it's a pheromones thing. There is something about Josh that is so uniquely attractive and sexy to me. And he wasn't my usual type at all. I went for moody and mysterious guys, usually actors. Josh is so different from any man I know."

The former 'Grey's Anatomy' star - who has 23-month-old adopted daughter Naleigh with Josh - says her favourite thing about her handsome spouse is the fact he can always cheer her up.

She said: "He's really charming and gregarious and he's super-positive about everything - like if the weather is crappy he'll somehow make it a good thing."