How accurate is the toddler height doubling rule for adult height prediction?

[Anonymous]

They always say to estimate a boy's future height, you double up the height he's at 2 years old. If he's 90 cm at 2 years old he'll be 180 cm (5'11) as an adult.

For girls, you double up the height she's at 18 months old. If she's measuring 85 cm at 18 months old, then she can grow to be 170 cm (5'7) as an adult.

This has happened with someone's faternal (boy and girl) twins. They're now 20 years old. The girl measured 88 cm at 18 months old and the her brother was 95 cm at 2 years old. As adults, the woman is now 5'9 and her twin brother is exactly 190 cm, almost 6'3. So what the doctor predicted at the time came out true in their case. Though how accurate do you think a growth predictor is? Is it like that most of the times?

[FreyaRed]

My younger brother wasn't the tallest in kindergarten and elementary school, while puberty he exploded and grow to 190 cm. I don't think making predictions in age of 2 makes any sense.

[Nikki1989]

Only insecure men care about height... and some fake pinks, of course.

[DryGermanGuy]

Sounds like an unserious pseudoscience. There are far more factors for height.

[Abbycado]

More dumb height questions. Smells like a dude in pink.