R2 visa and SSN

[MFR]

I have an R-1 visa and I've got a social security number. My family has just joined me 2 months ago. They have R-2 visa. I wonder if they are eligible for social security numbers. I know some similar cases where the family members with R2 visa got social security numbers. However when I applied for SSN for my wife and kid i was told at the office that they are ineligible because they are not permitted to work? What do you think?

[PraetorianXI]

They are not going to get a SSN if they do not "need" one... why would you want one for them?

[MFR]

for tax purposes

Thanx for the answer. I need them to get the child credit in the tax and get the deductible amount for the wife and child deducted from the taxable salary. in brief to decrease tehe witholdings from my salary.