It's a scientific fact

We tend to think of development being from birth and yes, certain aspects of development can be influenced by our experiences and environment (eg a baby can be at the stage where they are able to process language, but if they've been rarely exposed to it then they still won't be able to talk), so most people don't realise it is more than that.

My best friend was carrying twin girls and was 2 weeks less pregnant than me. Her babies were delivered by c-section at 37 weeks, when I was 39 weeks pregnant, and Freyja was a week late. Even though they are by birth older than Freyja by a whole month, developmentally they are still 2 weeks younger than her. It shows in that Freyja hits mental and emotional milestones before they do (the ability to reach for things, smile, laugh, understand words, babble etc), but she doesn't necessarily hit physical ones first (they cut teeth before Freyja and were able to roll before her, although she can sit, stand and take steps but they can't). She may have the mental capacity to understand and know how to crawl or roll etc, but she's smaller and has shorter limbs so physically can't.

Watching the 3 girls over the first few months and seeing how they developed at different rates is what got me so fascinated (some may say obsessed!) with comparing how individual babies are.

The best book to read (as in one that's designed for parents rather than academics!), is The Wonder Weeks. You've probably heard people going on about it on BellyBelly because it was difficult to get hold of, but it was republished in 2008 so is now readily available.

If you go to thewonderweeks website (google it) there's a good preview of the contents, as well as links to some other stuff you might find interesting. It obviously doesn't go into too much detail because they want you to buy the book, but I can send you a summary of the development points for 8 months on if you are interested?

Now, it's potty time!