The same principle that applies to co-signing also applies to borrowing...a big fat NO!!! DO NOT DO IT!!!!
Borrowing money can actually be worse. No you aren't chaining someone to an unwise purchase, but you are purposefully driving a wedge in your relationship.
Money can drive a wedge between any relationship. Even if it was not a loan, but a gift to help you with some type of purchase, there will be some underlying feelings there. (The only time there will not be feelings of disappointment, frustration, guilt, etc. is if the money was a gift out of pure generosity, not because the person felt you were in need).
Your brother loaned you $2000 for the down payment on your car with the agreement that you just make payments of $100 per month to him with no interest. What a great brother you have and a fancy new car! Life couldn't get any better!
Life is going well...you are making enough money to pay your car loan and your brother the $100 each month (you even made a couple extra $50 payments to your brother for good measure). Then your friend calls you and tells you that she wants you to come on a trip to Napa with her and your other 2 best friends!! Of course you can go - you'll even drive your new car!!
You had a great time in Napa and rush home to tell your family all about it...the fancy restaurants, the wine, the massages and so on. Upon hearing this your brother, knowing you still owe him $1500, walks out...and so begins the wedge...
It is just simply not worth it! A good friend may start avoiding you because she knows she owes you money, you may form resentment towards your child because she hasn't paid you back anything you loaned her but she shows up to your house in new clothes and a new hairstyle...
Please do yourself a favor and NEVER borrow money from family members or friends again! Also, if you are lucky enough to be the person with the loaning abilities please DO NOT DO IT! If you want to give someone a cash GIFT for no other reason than to be nice, go for it, but be very clear in your motivation and expectations.
If you are in debt with anyone, please move this to the top of your debt snowball and you will feel an enormous sense of freedom when this has been errased, I promise :-))