Adapted from the
Wonders of the Younger liner notes. '''Plain White T's''' • Tom Higgenson – vocals (lead on all tracks except 4 and 12), guitar, keyboards, celeste, percussion • De'Mar Hamilton – drums, percussion, vocals • Dave Tirio – guitar, vocals • Tim G. Lopez – guitar, lead vocals on tracks 4 and 12, keyboards • Mike Retondo – bass, vocals, keyboards, celeste, accordion, horns, woodwinds
Additional musicians • Dan Monahan – celeste, guitar, accordion, bouzouki, drum programming • Augie Schmidt – keyboards, synths, drum programming, strings, horns • Nick Rucker – additional instrumentation on "Rhythm of Love" • Jeremy Smith – piano on "Boomerang" • Mike Daly – pedal steel on "Killer" • Matt Rohde – piano on "Killer" and "Make It Up As You Go", B3 organ on "Make It Up As You Go"
Production • Joe Zook – mixing • Dan Piscina – assistant mixing •
Brian Gardner – mastering • Nick Rucker – additional production on "Rhythm of Love" • Dan Monahan, Augie Schmidt – additional production on "Irrational Anthem", "Our Song", "Cirque Dans La Rue" and "Make It Up As You Go" •
John Feldmann – additional production on "Map of the World" and "Last Breath"
Artwork • Enny Joo – art direction and design • Cliff Cramp – illustration •
Joseph Cultice – photography • Plain White T's, Mike Venezia – cover concept ==Charts==