When babies awaken: New study shows surprise regarding important hormone level

When babies awaken: New study shows surprise regarding important hormone level: Cortisol may be the Swiss Army knife of hormones in the human body -- just when scientists think they understand what it does, another function pops up. While many of these functions are understood for adults, much less is known about how cortisol operates in babies and toddlers, especially when it comes to an important phenomenon called the cortisol awakening response, or CAR.