B737-900
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 23
Communication Breakdown; Situational Awareness
ATC Issue All Types; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance
General None Reported / Taken
Human Factors
Aircraft X was transferred to the JOT/83 sector at FL320 tracking along J89.Approximately; 10-12 miles south of the RAN/JOT boundary I noticed Aircraft X executing a left turn.  I immediately called the JOT/83 sector to inquire and noticed the flight plan route had been changed to direct ROBBY.  I asked if the aircraft had just been turned and the JOT/83 replied in the affirmative and asked if I wanted the aircraft turned back.No transfer of control and aircraft was turned head-on into the Chicago Metro Southbound Departure corridor.What led to the event - In my opinion either an oversight or the culture of 'It's late [day] night' - procedures don't apply.Unless SOP's and other orders are considered optional; request control when issuing control instructions to aircraft not in one's area of jurisdiction.Carry out some performance management.
ZAU Center Controller reported that an aircraft was turned in his airspace without prior coordination.