Survey of romantic films over 30 years widens debate reignited by comments of Maggie Gyllenhaal, 37, about being told she was too old to star opposite 55-year-old manFemale leads are on average four and a half years younger than their male counterparts in Hollywood movies, and the age gap is only slightly smaller on films directed by women, according to new research.British film producer and writer Stephen Follows studied 422 romantic films that made more than $1m at the box office in the wake of Maggie Gyllenhaal’s comments last week about her experiences in Hollywood.