Complex sentence: In January 1968, Getty contacted Telfer for more information on her findings and she not only incorrectly assumed the acne-scarred Speck was an XYY male, but leapt to the egregiously false conclusion that Speck was the archetypical XYY male.
Split into simpler sentences: In January 1968, Getty contacted Telfer for more information on her findings. She not only incorrectly assumed the acne-scarred Speck was an XYY male, but leapt to the egregiously false conclusion Speck was the archetypical XYY male.