Dart and Cortina, separated at birth

Several years ago, a had a discussion about Dodge Darts with a guy who preferred the 1967-69 Dart's styling over the 1963-66 Darts, which I can certainly understand. What was strange to me was his comment on the early Dart styling in which he said "they looked like Japanese cars from that era!". This stuck me as odd, only because when it has come to automobile styling, nearly all 1960s and 1970s Japanese cars featured styling thaty was based on various European automobiles. The Datsun 240Z was aped from an XKE, the Mazda sedans were similar to Lancias, and the Honda 2000 cabriolets were based on popular Italian design.

But this guy had a point, however I contented that the Dart's styling similarity wasn't so much Japanese, rather it was what the Japanese were copying: English styling. Or was it American styling?

I've found making styling aspects of the 1963-1964 Dart (and Valiants) to be shared with some Brittish automobiles. Most notable are 1963-1965 Ford Cortinas. Below are several supporting images.

• The 1964 Dart GT side trim is very similar to the higher trim Cortinas (pictured in Collector Car magazine cover below).
• The 1964 Dart grille is similar to the design of the Cortina's, as is the hood design and chrome trim, and the headlight surrounds.
• the front bumpers are somewhat similar to the Darts, and the rear bumper's bumper shape that continues past the chrome bumper and into the quarter panel is very similar to the Valiants rear bumper design.

Both car designs appeared at the same time, and the similarities are striking. So who influenced who?