https://udel.edu/~mcdonald/mythtoelength.html
Toe length as a character
I did an image search for painted toenails and arranged the images from longer big toes to longer second toes. As you can see, the relative length of the big and second toes varies continuously; there aren't just two categories of toe length. Some studies have found about 5 percent of the populations sampled to have the big toe and second toe equal in length (Romanus 1952, Turgut et al. 1997). Hawkes (1914) said the big and second toes were the same length in only 0.1 percent of people. She also said about 6 percent of people had the big toe longer on one foot and the second toe longer on the other foot.
Toe length: The myth
In some people, the big toe is longer than the second toe (here called "L," for long big toe), while other people have the big toe shorter than the second toe ("S"). This is sometimes said to controlled by one gene with two alleles, with the allele for S dominant to the allele for L. There is no good evidence for this myth; the small number of studies of toe length give contradictory results.
Conclusion
Whether the big toe is longer or shorter than the second toe is influenced by genetics, but it may be determined by more than one gene, or by a combination of genetics and the environment. You should not use toe length to demonstrate basic genetics.