Tuesday, April 20, 2010

April Baby Quiz - Answers

Last Friday, we posted a new Baby Quiz. Here are the answers:

1. What percentage of total time sleeping do newborns spend in active sleep (dreaming)? ANSWER: 70-75%. Active sleep is the time when dreaming occurs. Newborn babies spend so much time in active sleep because the brain activity related to dreaming is important for babies' development. For more information about newborn sleep, read Part 1 of our recent series The Science of Infant Sleep.

2. Around 18 months, babies tend to have a vocabulary "spurt." About how many words does the average 18-month-old learn per day?

ANSWER: 3. It is amazing how quickly babies learn! For more information about language development during the second year of life, refer to Part 2 of the From Cues to Conversation series.

3. On average, how old are babies when they cut their first tooth?

ANSWER: 4 to 7 months. Teething is one part of life that is uncomfortable for everyone. It is physically painful for babies and emotionally painful for parents. Unfortunately, there is wide variation not only in the age at which the first tooth appears, but also in the amount of time it takes for teeth to cut through. In one of our upcoming posts, we will explain how babies' behaviors may change during teething and provide tips for making the experience a little easier on everyone.

4. Babies are born with all 5 senses (sight, hearing, taste, touch, and smell). Which of the 5 senses seems to be the least developed at birth?

ANSWER: Sight. When babies are born, they can only see objects that are 8-12 inches away. The other senses are much more developed. For example, a baby learns the sound of his mother's voice before he is born and can distinguish the smell of his mother within days after birth. For more information about newborn development, refer to the post Newborn Development: Reflexes Rule!

5. On average, how old is a baby who can sit all by himself and move a toy from one hand to the other?

ANSWER: 6 months. Babies usually begin learning to sit with support around 4 or 5 months of age. At this age, they also start trying to transfer objects from one hand to the other. After just a few months of practice, typically around 6 months of age, these skills become routine! Remember that all babies develop at their own pace and these ages are just averages. More information about infant development is available in the Infant Development series we posted last September and October.

So, how'd you do? We'd love to hear from you, so send us your comments. We'd also love to use one of your questions in our next quiz, so send those too!

Next time: Back to your questions!


  1. Just started reading this blog when helping a friend research infant sleep (She's a new mom of a 5 wk old and I have no kids, but my husband and I are planning to start TTC some time next year). I surprisingly got them all right except for the teething q! Thanks for the great posts and information. Keep up the great work!

  2. I'm looking forward to hearing more about teething. My little one's first tooth is just poking through now at 8 1/2 months!

  3. oh yes, my 3.5 month has started to teeth.