Thurgood Marshall, United States v. Estate Grace…
“ For these reasons, we hold that application of the reciprocal trust doctrine is not dependent upon a finding that each trust was created as a quid pro quo for the other. Such a 'consideration' requirement necessarily involves a difficult inquiry into the subjective intent of the settlors. Nor do we think it necessary to prove the existence of a tax-avoidance motive. As we have said above, standards of this sort, which rely on subjective factors, are rarely workable under the federal estate tax laws. ”
