Næss was born in Germany in 1937 to German physician August Oskar German Raab (1901–1993) and Kirsten "Kiki" Dekke Næss (1907–2001), a Norwegian national whose brother was philosopher and mountaineer Arne Næss.
Næss lahir di Jerman pada tahun 1937 dari pasangan dokter Jerman August Oskar German Raab (1901–1993) dan Kirsten "Kiki" Dekke Næss (1907–2001), seorang warga negara Norwegia yang saudaranya adalah filsuf dan pendaki Arne Næss.