It is said the nerve center is located on that spot, but not sure about the exact reason. Perhaps, it has something to do with the pigment in the 'tilak'..?
Yes. I also think that the nerve centre is located on the spot. Some people say to avoid bad people mesmerising girl, they used to keep kumkum there. I don't know whether iam correct.
YES ---- some of our friends are getting closer to the right answer.... have stated the right points... But hope it would be good if the answer is more finned.....
Tilak is applied to the forehead, because the kukmum used for applying tilak is made from turmeric. Turmeric along with being antibiotic, antiseptic, noninflammatory etc is also believed to keep evil spirits away! therefore this tradition!
There is a nerve connecting to the brain which is present between the eyebrows which connects the memory concentration of the body, so when we put tilak it constantly stimulates it and keeps it active
As tilak is made up of turmeric powder, which is very cool, so it makes a cool effect on that spot and good for memory.
Also its a delicate place so putting tilak protects it from direct sun rays.
In earlier times, The brahmin applied a white chandan mark signifying purity. The kshatriya applied a red kumkum mark.The vaishya wore a yellow kesar or turmeric mark.The sudra applied a black bhasma, kasturi or charcoal mark.Vishnu worshippers apply a chandan tilak of the shape of "U," Shiva worshippers a tripundra of bhasma, Devi worshippers a red dot of kumkum.
The Tilak have medicinal and protective functions. The pastes applied, gives cooling effect to the body.The Tilak bestow spiritual comfort and protection against demons, bad luck, and other evil forces. The place where we put Tilak is called Aajna Chakra and it gives concentration of spiritual energy on the forehead between the eyebrows.
The tilak is applied with the prayer - "May I remember the Lord. May this pious feeling pervade all my activities. May I be righteous in my deeds."
There is a small story actually behind this of me doing a sort of investigation regarding these customs.... :)
This started with the present custom of "Tilak custom"
My uncle was very strict in this custom. When I was small, he used to scold me and my cousins if we forget to put bindi. He used to take it very seriously.
One day I cried as he scolded me ;) Then my mom explained me and told that putting bindi on my forehead would help me and not others. Thus from that day I was just wondering why we have customs and whats the reason behind this!!!!