N.J. Stat. Ann. § 46:3-17

From and after February fourth, one thousand eight hundred and twelve, no estate shall be considered and adjudged to be an estate in joint tenancy, except it be expressly set forth in the grant or devise creating such estate that it was or is the intention of the parties to create an estate in joint tenancy and not an estate of tenancy in common, any law, usage, or decision theretofore made, to the contrary notwithstanding.