Answer the Landline

There was a time when we remembered phone numbers. Pre-mobile phones, we either wrote numbers down or stored them in our long-term memory.

I can still remember my parents’ landline number from fifty years ago. It was reinforced to me every time my father answered the phone. He’d recite the number to the caller instead of saying hello.

To this day, I’m not sure why he didn’t use a simple greeting. Back then, landline numbers in Australia were six digits long. As more people connected, the phone companies realised they were running out of numbers. Landline numbers grew from six to seven, and then to eight digits.

My father then recited all eight to incoming callers. When he made calls, he dialled numbers from memory. He never seemed to reach his cognitive load limit.

Cognitive load is a brain term used to describe how much we can hold in our short-term memories. Most adults can hold up to ten, which, surprise, surprise, is the number of digits in modern-day phone numbers.

Of course, we don’t need to worry about it because cell phones do the hard work for us. I couldn’t tell you my daughter’s phone number because I’ve never had to store it anywhere but in my phone.

Cognitive load has enormous implications for learning—more next time. Or, check out the teacher post in this week’s blog.