Can you really tell gender from height?

[Beach_Town_Brit]

What does everyone think, can you guess at gender from the height of young seedlings?

These are 5 Nirvana Mystery seeds that I've been growing out in coco under CFL for a friend. They were planted mid February so they're around 3 weeks old now. They were all planted at the same time and #s 2-5 all popped around the same time.

#1 is my my little weirdo, my case in point for "not all seeds are created equal." It took a whole week longer to pop and has lagged since.

Do you think I can call #5 as a male?
What about #3?
Are 2 & 4 likely females?

One or more could even be autos, can we tell?

No stakes here really, academic interest mostly. I'll likely give #s 2-5 to my friend this weekend, and she can learn to sex them as they grow out, it'll be her first grow

[NebulaHaze]

Taller or faster growing plants are sometimes male, but sometimes it's caused by genetics, strain, position under the light, or just plain luck with the individual plant You can start checking for pre-flowers now, though. Sometimes males show as soon as 3 weeks from seed, and pretty much every plant, both male and female, will be "showing" by the time they reach 6 weeks from seed, even if they're still in the vegetative stage.

[Beach_Town_Brit]

Thanks Nebula. I'll try and snap some more macro pics to see if can see the sex but I think it might still be too early.
The plants are going to their new home this week so it may be up to my friend to sex them.

[Beach_Town_Brit]

Here's a close pic, but I don't think I could call the gender yet...

[NebulaHaze]

Not quite yet, but that's a great picture!

[007]

Just wait for it to pop balls. They're unmistakable. I've had different phenos of the same strain grow wildly different plants, some I swore were males based on height and vigour, really not a hard and fast rule though.