Like father, like son — Arnold Schwarzenegger‘s 16-year-old love child is already showing off his genetic superiority in a Speedo … kicking ass at his high school swim meet this weekend.

Joseph Baena stripped down to his skivvies Sunday to represent his Bakersfield high school swim team — swimming butterfly no less — and his mom Mildred was right there on the deck cheering him on.

Joseph’s been busy the last couple months — as we reported, he just got his driver’s license in January.