Modern Human Intelligence occured when static Paleolithic [Genes] settlements interacted and intermingled with the spread of the Neolithic approximately 6000 years ago!
Human Intelligence came from when people from Poland & Ukraine conquered the world with Indo-European languages & Spread across the Balkans, Indus Valley, Mesopotamia, Anatolia, Greece & Even Egypt ect.
As from Eastern Europe the inventions of the Copper age, Bronze age, First Writing evidence, First wheel, First Wagon, First true Chariot, First chain mail armor, First Gold plating technology, First Composite bows, First Alcohol. First Textiles, First Tailored suites, First Block houses, First female fashion ect had spread from Eastern Europe into larger populated river valleys like Indus, Mesopotamia & Egypt.
Europeans. No one knows what these people looked like and as they spread throughout Asia and Europe they interbred with the peoples already living in the places they migrated to, and so today's Indo-Europeans are all an ethnical mix with both Proto-Indo-European and non-Proto-Indo-European origins
We know what they looked like they were Corded Nordics with R1a haplogroup.
They moved from Poland to Ukraine & Russia bringing R1a haplogroup East into Central Russian / Central Asian Andronovo culture.
Out of 10 human male remains assigned to the Andronovo horizon from the Krasnoyarsk region, 9 possessed the R1a Y-chromosome haplogroup and one C haplogroup (xC3). mtDNA haplogroups of nine individuals assigned to the same Andronovo horizon and region were as follows: U4 (2 individuals), U2e, U5a1, Z, T1, T4, H, and K2b.
90% of the Bronze Age period mtDNA haplogroups were of west Eurasian origin and the study determined that at least 60% of the individuals overall (out of the 26 Bronze and Iron Age human remains' samples of the study that could be tested) had light hair and blue or green eyes.
A 2004 study also established that during the Bronze Age/Iron Age period, the majority of the population of Kazakhstan (part of the Andronovo culture during Bronze Age), was of west Eurasian origin (with mtDNA haplogroups such as U, H, HV, T, I and W), and that prior to the 13th-7th century BC, all Kazakh samples belonged to European lineages
The Sintashta culture, also known as the Sintashta-Petrovka culture or Sintashta-Arkaim culture, is a Bronze Age archaeological culture of the northern Eurasian steppe, dated to the period 2100-1800 BCE. The earliest known chariots have been found in Sintashta burials, and the culture is considered a strong candidate for the origin of the technology, which spread throughout the Old World and played an important role in ancient warfare. Sintashta settlements are also remarkable for the intensity of copper mining and bronze metallurgy carried out there, which is unusual for a steppe culture.