The Secular Trend in Growth and Puberty Development

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: Gender Differences in Adolescent Development

You're on a roll. Keep up the good work!

Take Quiz Watch Next Lesson
Your next lesson will play in 10 seconds
  • 0:02 Puberty
  • 1:17 Secular Trend
  • 2:25 Causes
  • 4:18 Lesson Summary
Save Save Save

Want to watch this again later?

Log in or sign up to add this lesson to a Custom Course.

Log in or Sign up

Speed Speed Audio mode

Recommended Lessons and Courses for You

Lesson Transcript
Instructor: Natalie Boyd

Natalie is a teacher and holds an MA in English Education and is in progress on her PhD in psychology.

Teenagers go through dramatic physical changes as a part of puberty. But something odd is happening: puberty is starting earlier each generation. In this lesson, we'll look at the secular trend of puberty and its possible causes.


Ellie is 13 and her body is changing rapidly. A few years ago, she started developing breasts, and her hips are growing larger, too, as her body becomes more and more like a woman's. A few of her friends have even started their periods, and Ellie knows she's not far behind.

Ellie is in adolescence, or the period of life between childhood and adulthood. People go through many changes in adolescence, including physical, emotional, intellectual, and social changes. The physical changes that take place in adolescence are called puberty, which lasts for about four years and ends with the ability to reproduce. For girls, this means that they get their first period. For boys, it means that they are able to produce sperm.

Puberty has always been a part of human development. Ellie is just the latest in a long line of people who have gone through it, all the way back to caveman days. But puberty is different now than it was in caveman days. In fact, puberty is different now than it was just a hundred years ago. Let's look at the 'secular trend' in puberty that has happened over the past century and the possible causes for it.

Secular Trend

Like generations of women before her, Ellie is going through puberty. But there's a difference in Ellie and her ancestors. Ellie's great-grandmother didn't start developing breasts until she was 13, and Ellie began puberty at age ten.

The secular trend in development is the fact that puberty is starting earlier for boys and girls now than it did a hundred years ago. The end of puberty (when girls get their period, for example) has leveled off somewhat, but the beginning of puberty is still getting earlier, especially for girls. So, Ellie is not unusual. It's common for girls today to start developing breasts (which is often considered to be the onset of puberty) much earlier than their ancestors did.

This would seem to be counterintuitive because the onset of puberty is largely influenced by genetics. That is, girls and boys have a genetic predisposition for when they go through puberty. And since that's the case, then it makes sense that Ellie would start and end puberty at a similar time to her great-grandmother because they are related and share genes.


So why is the secular trend happening? Genes aren't destiny, and environmental factors can play a large role in human development, including puberty.

To unlock this lesson you must be a Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use

Become a member and start learning now.
Become a Member  Back
What teachers are saying about
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create an account