Nielsen v. Bell, 2016 UT 14

A four-year-nine-month-old boy threw a rubber toy dolphin that struck Ms. Nielsen in the eye; she lost vision in that eye and sued for negligence (against the child) and negligent supervision (against parents).
Nielsen abandoned claims against the parents for negligent supervision; the district court granted summary judgment for the parents but denied summary judgment on the negligence claim against the child.
The central legal question presented on interlocutory appeal was whether Utah law recognizes a conclusive minimum age below which a child cannot be held negligent, and if so what that age is.
Utah precedent contains mixed signals: some older language suggested a seven-year cutoff, other cases treated capacity as a jury question for five- and six-year-olds, and a 1920 case (Herald) suggested a nearly-five-year-old could not be contributorily negligent as a matter of law.
The Utah Supreme Court reviewed common-law approaches (Illinois rule, Restatement) and cognitive-policy arguments and resolved the legal question de novo.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether Utah recognizes a categorical minimum age below which a child cannot be negligent	Nielsen: no fixed cutoff; capacity should be considered case-by-case	Child: Utah precedent supports a categorical rule (argues seven or at least five)	Court adopted a categorical rule: children under 5 cannot be held negligent as a matter of law
Whether Utah has adopted the Illinois 7/14 rule (conclusive under 7, rebuttable 7–14, rebuttable capacity 14+)	Nielsen: oppose categorical age cutoff	Child: argues Utah follows Illinois rule (conclusive under 7)	Court rejected that Utah conclusively adopted the seven-year rule; prior statements were dictum and some cases treated 5–6 year olds as jury questions
Whether the four-year-old defendant in this case can be held negligent	Nielsen: factual dispute precludes summary judgment; four-year-old may be liable	Child: under-5 immunity should apply and summary judgment should be granted	Court reversed district court and granted summary judgment for the four-year-old (under-5 immunity)

Nelson v. Arrowhead Freight Lines, 104 P.2d 225 (Utah 1940) (earlier dictum suggesting a seven-year rule but not controlling)
Mann v. Fairbourn, 366 P.2d 603 (Utah 1961) (refused to apply a categorical seven-year rule; held capacity may be a jury question)
Donohue v. Rolando, 400 P.2d 12 (Utah 1965) (recognized very young children may be judicially deemed incapable of negligence)
Rivas v. Pacific Financial Co., 397 P.2d 990 (Utah 1964) (treated a child just under six as a jury question on negligence capacity)
Kilpack v. Wignall, 604 P.2d 462 (Utah 1979) (applied a presumption of incapacity for a seven-year-old plaintiff in contributory negligence context)
Herald v. Smith, 190 P. 932 (Utah 1920) (held a four-year-ten-month-old plaintiff could not be charged with contributory negligence as a matter of law)
Roper v. Simmons, 543 U.S. 551 (U.S. 2005) (cited for the legitimacy of bright-line age rules in constitutional context)