Let me add that it is true of MOST breeds. Many breeds, however, generally same sex get along. Not so much with basenjis. In fact if you have someone trying to tell you it's an old wives tale, run from them as fast as you can.
Next advice… get your dog tested for Fanconi if you haven't already. Please. The earlier you KNOW the better chance you have of keeping your pet healthier. If you got this one from a breeder, contact the breeder to get it's parents' AKC numbers or proof of Fanconi testing. If they are both clear, or only one a carrier or affected, you don't have to test your dog as it cannot have Fanconi. If you can't get proof, then do the DNA test.
THEN make sure you have proof that the puppy or dog you get is either clear or a carrier. .. or read up and make SURE you are willing to follow the protocol and take care of an affected dog. I have no idea if Medfly tests... but nearly all breeders do and Camp Basenji in FL does. Often breeders may have an adult or older puppy to place if your heart isn't set on a puppy.
Good luck and post pictures!