As soon as I'd position my little guy Theo within sniffing distance of my exposed nipple, he'd start crying frantically and shaking his head side to side maniacally like a shark about to tear my poor boob to shreds. His twin brother, Nate, would either calmly latch on to my other breast or flatly refuse it (and more often the latter, frustratingly), but he was never the crying, anxious blob that Theo was. It always felt like, if Theo had to wait another second for my milk, he'd spin out of my arms and into the kitchen, where he'd open a gallon of 2% and start guzzling. Yet when my nipple and his moving-target mouth finally connected, bafflingly, Theo would freeze. No sucking, no swallowing, not even any more shaking. He was like a quarterback who talked a good game but had no idea what to do once he got the ball.

After a couple days of this, I was reading the book Your Baby's First Year, from the American Academy of Pediatrics (AAP), and came across a section, called Getting to Know Your Baby's Feeding Patterns, that described five different nursing personalities, including the "Excited Ineffectives" -- infants who "become frantic at the sight of the breast."

What the…?! Was the AAP spying on us? Because Theo was both excited and ineffective -- and he wasn't alone. The breastfeeding types were characterized by Yale University researcher Edith Jackson, M.D., during the 1950s, when she observed hundreds of nursing newborns in the university hospital's maternity ward. If you had a healthy, full-term baby, you might recognize your tiny sucker in one -- or all -- of these profiles (adapted from the AAP's Your Baby's First Year and the original Yale study).

So, what's your baby's nursing style?